I introduce this topic with one question: wWhat is Friday The 13th?

sSeriously, I really don’t know what theis mean s.¶
I thought this was about the very popular movie with the same name, Friday The 13th, when we have the mainith the character Jason Voorhees.

1. I can see two things that you were trying to say
“What this means”
“What is the meaning of this?”
I put the first option because it seems more appropriate, “What is the meaning of this?” is often a saying used to ask what is happening when people are acting up, I’ve mostly seen it used in media though.
2. In last sentence, “when” is used incorrectly. You’d want to use “where” there. But that sentence sounds odd, so I just ended up rephrasing it.

To be honest, guys, please don’t put me on the cross, I never watchedbut I’ve never seen this movie before...

1. “I have never watched this movie before” works just fine, but “I have never seen this movie before” sounds more natural and is normally what we say.
2. Additionally, using the contraction “I’ve” can also make the sentence sound better.

It’s okay, I haven’t seen that movie either ;)

ifIt’s hard to believe.. I can heard your murderous thoughts, BUT!

When writing, if you’re trying to write something formal like an essay or a book, you shouldn’t capitalize every letter of a word unless you’re abbreviating something. You should just use an exclamation mark instead, but here, since I can see you’re going for a very casual, silly tone, it’s perfectly fine :)
It’s perfectly fine to do this in informal settings, like texting. I do it all the time to put emphasis on my words.
Just keep that in mind though if you already didn’t know

I was never the type of person who watchedenjoyed (scary?) movies, i. In fact, I’ve only watched the ones that were on my TV.

1. I’m not sure if you meant scary movies or just movies in general
2. You can also remove “of person” from your first sentence if you want to, since it’s a common phrase to say “I’m not the type to…”
3. Since you’re referring to the past, you should use “I’ve/I have”.

I justonly remember one, "Nightmare On Elm street " ”.¶
So, someone who has a good soul, could you explain what the hell means Friday The 13th is and what It'y it’s so important?

Friday Tthe 13th?

Short articles such as "the" generally aren't capitalised in titles.

I introduce this topic with one question: what is Friday Tthe 13th?

sSeriously, I really don’t know what ithe mean s.¶
I thought this was about the very popular movie with the same name, Friday Tthe 13th, whenre we have the main character Jason Voorhees.

(1) Alternatively: "Seriously, I really don't know what the phrase means."
(2) Movie titles are also titles, and follow title capitalisation rules as well.
(3) "When" is used with respect to time. "Where" is used when referring to situations in general, and is expected here.

To be honest, and guys, please don’t put me on the cross, Ibut I've never watched this movie before...

(1) You can also use parentheses: "To be honest (guys, please don't put me on the cross), I've never watched this movie before..."
(2) You can also use em dashes, which are functionally identical to parentheses here: "To be honest—guys, please don't put me on the cross—I've never watched this movie before..."

ifIt's hard to believe..I can heard your murderous thoughts, BUT!

Mind the tense.

I just remember one, " called "A Nightmare Oon Elm sStreet " ".¶
So, someone who has a good soul, could you please explain what the hell means Friday Tthe 13th means and what Iy it's so important?

(1) I believe the movie is called "A Nightmare on Elm Street".
(2) Short prepositions like "on" are also not capitalised in titles. However, note that the article "a" is capitalised here because it is the first word in the title. Generally, the first and last words in a title are always capitalised, no matter what they may be.
(3) Alternatively: "could you please explain what the hell is meant by Friday the 13th and what about it is so important?"