What A Private Person I Am!

This sentence is correct! But I think "introvert" or "shy" are better for "内向的"
"Private person" is not the same as "introvert." Private person is someone who doesn't talk about their personal life.

I participated in an annual party and madgave a speech.

More natural: I went to an annual party and gave a speech

Otherwise, I only talked with a guyto the guy sitting next to my seate, and I forgot to say hello to the VIPs (very important persons/people).

I didn't communicate with the people whom I needed to do that.

When I was 14 years agoold, I liked a classmate girlgirl in my class and I talked with her a lot.

ThenSomehow, I wasn't able to talk with her somehowanymore.

Talking withto a girl from a different class girlsomehow seemed somehow wrong forto me.

After sSeveral months later, her house was burnt completely burnt down.

A fire hit her housHer house caught on fire.

This sentence is a little redundant. You can say "several months later, her house was completely burnt down in a fire."

After school, while I went home, I met(One day) On my way home after school, I ran into her, but I wasn't able to say anything to her, n. No consolations, no or cheering her up.

"I met her" usually means meeting for the first time.
"I met up with her" usually means you planned to meet at a place.
"I ran into her" or "I bumped into her" usually means on accident / unplanned. Similar to ばったり会う。

I regret (that) I wasn't able to speak to her.

One day when I was 4 or 5 years old, I didn't go to the kindergarten because my family and I were going to have(on a trip) to Osaka for investigating my visual functionto have my vision checked.

"on a trip" sound like it is for fun.

At around 11 am, my grandmomther brouhght me to a neighbor's candy shop to get some caramel for my trip.

Then, the kindergarten was over, andclass ended and I ran into my classmatesas they were going home and I encountered them.

I tried to hide myself from their vision,m but I failed.

I wasn't able to saymake any excuses to them at that time.

Probably this was the first evidence that I've bee(or "sign") that I was an introverted.

Otherwise than that, I only talked with a guy seated next to my seate, and I forgot to say hello to the VIPs (very important persons/people).

I failed as a successful/cooltop tier businessman.

I didn't communicate with the people whom I needed to do thatcommunicate with.

I thought I was rather a talkative as a boy.

When I was 14 years agoold, I liked a classmate girlgirl in my class and I talked with her a lot.

Talking with a girl in a different class girl seemed somehow wrong for me.

After several months, her house was burnt completelyburned down.

The sentence you wrote isn't wrong, but it's much more likely to be seen in a context where you've already provided some information about her house burning. For example, "A spark caught fire. After several months, her house was completely burned."

A fire had hit her house.

Using the past perfect tense hints at the fact that this is not a past event that comes after the event in the previous sentence but rather is a past event that serves to explain the event in the previous sentence.

After school, while I wenton my way home, I met her, but I wasn't able to say anything to her, no consolations, no cheering up.

or "while I was going home"

One day when I was 4 or 5 years old, I didn't go to the kindergarten because my family and I were going to haveon a trip to Osaka for investigatto examinge my visual functionimpairment.

At around 11 am, my grandmom brouhght me to a neighbor candy shop to get some caramel for my trip.

Then, the Kindergarten was over, andhad dismissed, and I encountered some of my classmates were going home and I encountered them.

I tried to hide myself from their vision, but I failed.

"myself" is optional
or "from their field of view" or just "from them"

I wasn't able to say any excuses to them at that timetell them why I didn't go to kindergarten.

Probably this wasThis was probably the first evidence that I've been am introverted.

or "This is probably my earliest memory that shows that I am [introverted | an introvert]."

I participated in an annual party and madgave a speech.

Otherwise, I only talked with a guy next to my seat, and I forgot to say hello to the VIPs (very important persons/people).

I failed as a successful/coolocially talented businessman.

I didn't communicate with the people whom I needed to do thatalk to.

I think that I'm very introverted.

I thought I was rather a talkative as a boy.

When I was 14 years agoold, I liked a classmate girlgirl in my class and I talked with her a lot.

The next year, there was a class shuffle, and I ended up in a different class from her.

Then, I wasn't able to talk with her somehowanymore.

Talking with a different girl in class girl seemed somehow wrong forto me.

After several months, her house was burnt down completely.

After school, while I went home, I mI wen to meet her, but I wasn't able to say anything to her, no consolations, nmeaningful to her, such as a consolation or something motivational to cheering her up.

I regret that I wasn't able to speak to her.

One day when I was 4 or 5 years old, I didn't go to the kindergarten because my family and I were going to haveon a trip to Osaka forto investigatinge my visual functionproblems with my eyes.

At around 11 am, my grandmom brouhght me to a neighborhood candy shop to get some caramel for my trip.

TBy then , the indergarten was over,class was over for the day and my classmates were going home and, but I encountered them. on their journey back.

I wasn't able to say any excuses to them at that time.thing to them.

Probably thism, that was the first evidence that I've beensign that I was introverted.

Otherwise, I only talked with a guythe person sitting next to my seate, and I forgot to say hello to the VIPs (very important persons/people).

Otherwise, I only talked with the person next to me and forgot to say hello to the VIPs.

I didn't communicate with the people whom I needed to do that.

I thought I was a rather a talkative boy.

When I was 14 years agoold, I liked a classmate girl and I talked with her a lot.

Then, IAfter that, I somehow wasn't able to talk with her somehow.

Talking with a female classmate from a different class girl seemed somehow seemed wrong forto me.

I'd probably say: Talking with a girl from a different class felt wrong to me.

After several months, her house was burnt completely burnt down.

After several months, her house burned down.

After school, while I wentas going home, I met her, but I wasn't able to say anything to her, ---no consolations, no cheering up.

I regret that I wasn't able to speak to her.