Hi! I was wondering if anyone could recommend a manga involving a friendship (not a huge fan of romance) between a delinquent and non-delinquent. I'm fine with most genres so please recommend anything 🙂

Lookism is a great example of what you want later on in the series
Mob Psycho 100 has a bit of that going on.
Ocha Nigosu is about a delinquent who wants to change his ways and is only a delinquent by chance. He tries to be normal by making normal friends but he just can't let go of his ways. Exact reverse to what you want.
Akumetsu is also a reverse of what you want where the MC is basically a brutal delinquent (can a terrorist be called a delinquent?) and he strikes a friendship with a normal girl (no romance), though thats not the main plot.

Currently getting my life together~ (unsuccessfully)

Banana Fish, definitely. The bromance between the protagonist (gang leader) and deuteragonist (all-round good boy) is even the main relationship in the story, which is pretty rare for your specifications.

Fly, Daddy, Fly -- It's a cross-generational friendship, though, so the dynamic is different.

Tekkon Kinkreet, sort of. It's a very unconventional story, so not the typical delinquents (or non-delinquents, for that matter).

Sakigake!! Cromartie Koukou, but a bit of a warning: it's total crack. Hilarious crack.

Maybe Chess Isle, but I haven't read it yet - only skimmed - so no guarantees.

Thank you so much! I'll check them out!