Any advice on hooking up with a guy for the 1st time as a bi guy?

Warning I’m going to ask some pretty graphic questions?

A bit of backstory, I’m 21 and have basically been attracted to guys and girls my entire life, I kind of thought that was the norm until I was like 8 when I found out that most of my peers were mainly attracted to the opposite sex.

Also btw, I’m mostly in the closet except for my parents and close friends.

I basically have no sexual experience with guys except for when I was like 12, my friend and I used to make out occasionally so we could ‘practice for girl’ lol.

There weren’t many openly gay or bi people during my time at my secondary school and from about 18-21 I was in relationship with a girl.

We’ve been broken up for a couple of months now and I feel this is my time to get back out there finally experience bussy.

I downloaded Grindr like three days ago and I’ve already had many hot guys who I would consider to be out of my league hit me up and ask if I wanted to hook up. I’ve arranged to meet this one guy in a few days, but I’m a little bit nervous.

Here are some questions I have:

Is my dick big enough to satisfy a man?

I’m about 6.5 inches and pretty girthy, and I sent a dick pic and he says it’s hot but he also sent me some nudes and I think he’s bigger than me. I also spoke to another guy and when he asked for a dick pic, I sent it to him and he said he only hooks up with guys who have 7.5 inch minimum, like come on man how many guys have a 7.5 inch dick, that’s a ridiculous standard. I’ve never really been insecure about my penis until i joined Grindr.

What positions should I do?

Because I’ve only had sex with women before this, I’m kind of only used to like ‘hetero’ positions like missionary, doggy, cowgirl i know some of them like doggy are pretty common in gay sex but what other positions should I know?

What do men’s buttholes feel like compared to vaginas?

When I was in a relationship my ex girlfriend we never did Anal. Are guys buttholes tighter or looser on average than vaginas. Is there anything i should expect going in?

Sucking dick?

I’ve never sucked a dick before. He hasn’t specified that he wants head but just in case, is there anything I should I know. I’m pretty sure I don’t have a good gag reflex. Should I like practice on a carrot or something.

Eating ass:

He did mention that he likes being rimmed. I’ve never rimmed nor been rimmed. I’m down to rim but I have literally know idea what I’m supposed to do. Do I just stick my tongue inside and kind of lick it up and down or is there some tongue technique I need to know? Is it similar to eating pussy?

Bottoming? I never taken anything in the ass, (not even a dildo), I’m pretty nervous about getting penetrated because it kind of makes me feel powerless and I’m not really into that. The guy I’m meeting up with specified that he’s a bottom so i probably won’t take any dick. But does being bottomed live up to the hype? Should i maybe find I guy with a smallish dick to get bottomed from or should I find a dildo and do self prostate stimulation?

STD’s? One of my biggest concerns is STD’s. The guys profile says he negative and has been tested and is on PREP. Should I get tested afterwards? Should I get on PREP? How common are STD’s?