Solo Ghost King VS Fighter | Solo Mastery Challenge | Dark and Darker 

Some cheap mechanical keyboard I bought off amazon for like $20

just keep trying bro, I was like you. I also started this wipe but I just kept trying and trying. Watching tutorials/guides is only gonna be so effective. You need to just keep trying with squire gear over and over, I'd suggest first trying to kill him as warlock as that is the easiest way for a beginner to kill bosses.

You need the mechanical skill/knowledge to consistently kill bosses. Plus the strategy can change depending on what class you pick, and certain classes are much better at bossing then others. Depending on your skill level, either just keep running it back with base kit and studying tutorials until you get it, or keep playing normally until you are confident you know how to deal with PvE and PvP (the worst part of bossing is people jumping you during the boss or after when you might be low hp, and stealing all the loot).