Welcome!
First thing I’d recommend: we are clearly not the first people to ask that question. There have been generations of radicals who spent their lives combatting capitalism with different strategies and tactics. Some of them were kind enough to write them down, the least we can do is pay them back by reading what they had to say with an open (but critical) mind.
I’d recommend starting with Socialism: Utopian and Scientifi. There were many socialists in the 19th century with various theories about how they could triumph over capitalism. Some thought it would come easily, they naturally just had to appeal to workers’ interests and the workers would take it from there. They were wrong (see: Paris Commune). The movement away from capitalism is an enormous task and it requires us to be fully aware of its scale if we are serious about accomplishing it. Marx and Engels are widely acknowledged to be the thinkers who properly assessed the enormity of the task, and whose theories have proven most useful for those who wanted systemic change.
As to what I think you should do in the real world: join an organization. Anything is (probably) better than nothing. The US has the PSL, other countries have lots of different movements and parties. If your org is more concerned with infighting than mutual aid, you’re better off going to something else (hell, you might get farther in helping people with a church than a sectarian org).
You should be able to contact your admins so they purge your account. Purged accounts have all the content they ever published scrubbed from all databases on Lemmy. I’m not entirely sure how it works if there’s an instance that is defederated from your home instance after you post something and it gets federated to them, I assume it wouldn’t be deleted in that case so it would still be available online there, but certainly a lot harder to track down.