You only started a couple days ago. Give it a month, then a couple more months. Keep working on the puzzles, going through the lessons and analyze your games after you play them.
Chess is a very complicated game and it will take time to become good at it, but you are doing OK and I am sure you will improve. Just have some patience.
I feel like this site has a really steep learning curve. For a minute I kept getting connected with people of significantly higher level than me and in a few I think I actually did pretty well, but now even with people supposedly "Matched to my level", I find myself getting outplayed really quickly. I'm thinking maybe I need to play on a site where the player base is a lot more on my level or with some guidance of some kind.
I've tried puzzles and I've read through the lessons. I even tried following many of the "opening principles" to which I've been destroyed even following them. I'd be willing to learn more from playing if it didn't always end up completely annihilating my W/L/D record and tanking my score.
I haven't broke past the 400s since I started and that's even with some relatively even games with higher ranked players and some in which the game went well up until the end game. And with people around here brushing off my score as just being a blunderfest, it's a bit disheartening. I'm pretty sure I have a decent idea of what I'm doing.