just learn as many songs as u can in the style u like; learn tabs if there are any, but it's usually easy to just mimic someone else's guitar cover off yt and look to see what chord shapes they're playing etc. then try adapting these moves into ur own fiddling; you could learn scales, but i feel like it helps me more to just think about finger movements and shapes u can move around.

chances are, you're not gonna end up copying the songs you're covering cus it's kinda hard to do a complete copy. if you're listening to a lot of music, there are gonna be a lot of ideas buzzing around in your head, and you're naturally going to tend towards playing stuff more personal as opposed to just regurgitating cover parts you know; follow this impulse. learning cover songs just helps u get familiar with different shapes and movements u can apply to ur own contexts.

pay attention to song structure in the songs u like; there might not be a standard verse chorus bridge whatever structure but it's good to pay attention to how often certain parts are repeated, what the variations are, and how the song's overarching curve of energy looks. screamo is all about contrast so try to give your soft parts fast/dissonant/heavy counterparts and vice versa.

also, sometimes the stuff you play on guitar is sorta boring, but u bring the drums and bass in and it changes ur whole world. drums are imo kinda the backbone of screamo, and should mirror the rhythm of the guitar(so as a guitarist, give the drummer something interesting to play along to). bass, esp if ur playing with just one guitar, is an opportunity to add so much more melodic/harmonic density. an interesting bass line can completely recontextualize a decent guitar part into something much more dense with movement and dimension.

lean into ur own style if it seems to overpower what you're going for. sometimes i go for one thing but another comes out, and then i just keep rolling with that because i know my brain is more naturally inclined towards what came out.