Charlie was determined to introduce me to her ex-boyfriend Benjamin.

The three of us decided to meet at thea restaurant.

On theThat day, Charlie was dressed so well so, she's looked stunning.

He, Benjamin enteredgot to the restaurant 20 minutes late.

He had gray hair, and blue eyes.

Charlie and Benjamin hugged so long so I, I just had to stand behind them awkwardly.

I cleared my throat, then they apologized and we sat at the table.

They said sorry to me and we sat on the table.

combine with above sentence

I was an applicant for a grant to finish my field research and her ex was administrating it.

I was supposed to saytalk about my proposal to him.

While Charlie was atin the ladies bathroom, I brought it up, but Benjamin didn't listen my story.

But Benjamin didn't listen my story.

He just saitold me toI should break up with Charlie because he justafter seeing her for the first time in a long time, he realized how much he missed her when he met her after a long time.

I said, of course said "No!"

He was a totally dope.

It was my first try to walk(walking)ime trying to walk around the lake morefurther than that I used toually walk.

But I couldn't hikewalk around the whole lake.

I would keep the verb consistent with what you used earlier. Hike and walk have different meaning and if you were doing something more like a hike then it would be best to hike as the consistent verb

If I did, it would double the timetake twice as long.

original wasn't wrong, but this is how I would say it.

I didn't take my phone, I wanted to measure the distance of the walk but more than that, I wanted to not have my phone with me.

I wanted to measure the distance but I determined to leave it.

combine with above sentence

Charlie determincided to introduce me to her ex-boyfriend Benjamin.

The three of us decided to meet at the restaurant.

On the day, Charlie dressed well so, she' was stunning.

I also madestyled my hair.

He,When Benjamin entered the restaurant he was 20 minutes late.

I think it is best to have the sentence in past tense, as the previous sentences.

Charlie and Benjamin hugged for so long so, I had to stand behind awkwardly.

They said sorry to me and we sat ondown at the table.

I was supposed to say aboutmention my proposal to him.

But Benjamin didn't listen to my story.

He just saitold me to break up with Charlie because he had just realized how much he missed her when he met herseeing her again after a long time.

It was my first try to walk(walking) around the lake more thanime I had tried to walk around the lake this far, further thatn I used to walkhad walked before.

I wanted to measure the distance but I determincided to leave it.

I coulddecided to hike on the opposite side of the lake and see the reflection of the sun over the lake.

I haved been living this town quite a long time but I didn't know this place was exist.

There were a couple of houses at the end of the roads, apart from a town.

Some of the roads between the trees were factitious.

I decided toI would come back again and I should got back home before it gets dark.

Charlie determincided to introduce me to her ex-boyfriend Benjamin.

The three of us decided to meet at the restaurant.

On the day of the meal, Charlie was dressed well, so she's looked stunning.

I also madestyled my hair.

He, Benjamin enteredturned up to the restaurant 20 minutes late.

He had graey hair, and blue eyes.

'gray' is American English, 'grey' is British English. I am British, so I've corrected it, but I am not sure which version of English you are writing in.

Charlie and Benjamin hugged so long so I had toeach other for a long time, while I stanood behind them awkwardly.

They said sorry to me and we sat onat the table.

I was ain applicantthe process of applying for a grant that I needed to finish my field research and her ex was administrating itoverseeing the grant approval process.

I was supposed to saytalk about my proposal towith him.

While Charlie was atin the ladies room, I brought it up.

But Benjamin didn't listen my storyto what I was saying.

He just saitold me to break up with Charlie because he just realizsed how much he missed her when he met her after a long time.. It had been a long time since they had last seen each other.

'realized' is American English; 'realised' is British English.

I would break this sentence up because it is quite long and has a lot of information in it.

He was a totally dope.

It was my first try to walk(walking) around the lake more than that I used to walkattempt at walking further around the lake than I had previously.

If I did, it would double the timehad done, my walk would have taken twice as long.

I wanted tothought about measureing the distance but I determincided to leave it behind.

I could hike to the opposite side of the lake and see the reflection of the sun over the lake.

It gave me a very different feeling thanfrom usual.

I have been living in this town for quite a long time but I didn't know this place was existed.

NThere were narrow roads were along the lake.

There were only a couple of houses at the end of the roads, apartside from athe town.