A green alien babe

Get plastered and hit on Orions.

Check the stardate and Captain's logs to see if the Mirror Mirror event has happened yet. If it has, I would immediately get Spock and Scotty to figure out a way to get back to the mirror (our) universe, slingshot around the sun to travel back to 1986, and kill Trump

Change the shirt color of some crew so that red is no longer used... saving hundreds of lives.

I'M A MIDDLE AGED WHITE MALE?

I don't care what we're doing, because I know I'm all set!

Am I aware that I wasn't Kirk until I just woke up? Or have I just hijacked his life and all his past memories and knowledge?

If I'm me but in his body, first thing I do is resign, given that I'm utterly unqualified.

Hang out with Spock for a bit and tell him I isekai'd into his captains body and get him to help me I guess.

Bring back the manly Starfleet mini dress.

First star on the right, and straight on til morning.

shirt spontaneously rips

I'm pretty regular, so I'd have to go and squeeze out a Captain's log.

Bring me to the Orions

Phone the last Jedi and tell them somehow palpatine returned

Spock

Sing Row, row, row your boat while camping with Bones and Spock.