I don't like jeans either, specially the basic bitch blue ones, though they can look good.
Overall you want clothes that fit you well, not baggy at all, you wanna look tiiight if you wanna look sharp.
Yeah that's a bit of a problem, do what you can to lose weight, you will look better (and have a easier time shopping good clothes, I think), but that said, even if you have some extra weight (healthly), you don't wanna hide it on baggy clothes, will only make you look fatter.
Leather jackets are cool man! Cliche, but cool, dunno why you don't wanna use them (I don't use them that much because here in Brazil it tends to be too warm for me to feel any confortable in them, colder days are rare).
I would you recommend just go with some stilish shoes, some basic tight pants (like in the shape of your legs, not like your balls will bust out of them lmao) and some... button down shirts? Those look super cool for warmer weather, even basic t-shirts with cool prints can do it, if they are your size, go the lower size you're confortable with. For colder weather, get a cool parka like that guy from Oasis, they look bitching cool, stilish scarfs, the world is your oyster, there's lots of options when you can wear a lot of cloth. I have a puffy jacket that makes me look super buff, too bad I use it like twice a year because of how little actually cold days we have here. My friend Mr. P uses a big like... furr? jacket, but it's not like those lady furr jackets, more like "big classy guy" type of stuff. It's really cold, use your clothes to make you look even bigger/stronger.
Important things are: clothes fit you, smaller size you can wear confortably, so they show your body. Also, contrast is big, you gotta look at all the pieces and see how they fit or not in color, do your best to stand out (in a good way lmao). Generally a cool good outfit will have like two main colors, one lighter one darker, then some details in some other colors, probably also contrasting a bit with those, but not much, the main contrast should come from the two main colors, I think. It's kinda hard to explain without examples but look up there and try to find what you think looks good on the internet.
Also cool accesories, those fuckboy type of bracets, like leather/fabric ones? I don't even know what they are lol, but you no doubt must know what it is, I don't use them myself, as I already have my stilish glasses, but I think they are great (if you have to use glasses, spend some extra to get some really cool ones that look good on you, it's worth it). Can't think of more cool accesories but there must be others out there, I'm not big on clocks but those can look cool as well, chains if you're into that sort of thing. Accesories can project that fuckboy vibe miles away, when the rest of your outfit already looks stilish. But focus more on the basic fashion for now, I would say.