What should i do next?

I know i probably need alot of work to catch up to anyone but i heard about this mihawk thing and i hope to get here.

My units worth mentioning

Luffy 3* Max level (20)
Zoro Pound 4*
Red Hair Shanks 5*
Impact Ussop 4*
Sanji v2 3*

Any suggestions on what i can do to catch up / what to farm/ hope to pull etc?

With your current team, you have no time to catch up and become strong enough to take down mihawk which is next week.

sniff, I figured out about this game 2 days ago. sad day for me

Would you recommend me start over again to Reroll? I am only at Arlong Park and i thnk i'm around lvl 23-26?

It depends on what type of team you want. If you want a psy team you should keep your account and level up shanks and get other pay units. But if you want almost any other team I think you should reroll

Basically, so I can get the necessary troops from the events(i'm assuming they are limited) Unless mihawk is a recurring event i.e. you can obtain him again if the event should be sent out.

your only sole hope would be to finish the story and farm laboon, literally the last 2 chapters of the game.Team up with a friend captain nefertari vivi (4 star) or princess vivi (5 star) and you can take mihawk albeit cheap way but still a win is a win. There are a gazillion threads on this forum on how it works, have a look under the guides section for a extensive mihawk prep guide made by forum admin.

I will do that when i get home from work. Thanks

Mihawk event is recurring but there is a cycle of events you will have to wait for so while it does happen again it will be months down the road.