How do I git gud?

So I bought the game a couple days ago and I have been playing it a lot, I've never touched a souls/soulslike game prior to this and I simply suck since the game is obviously very difficult.
Anyways, I haven't defeated Margit yet, I can at best wipe out the giants that are to the right-ish of warmasters shack on the map. I can't even get remotely close to defeating the first boss (the giant guy covered in gold riding on a horse) and right now I'm trying to defeat the bloodhound knight and out of the 30-ish times I've fought him now, I've only managed to parry him once.

So please, give me all your tips on how to get good.