I looked at a few of your games and nothing really stands out as "fix this and you'll improve right away"
I mean, obviously the normal stuff: challenge yourself to follow the opening principles more closely and blunder check, but that takes time and is something every new player needs to work on.
I think you just need to play more. Chess takes time. Be sure to analyze your games and try to find one big mistake, and think about what you'll do differently next time. It could be something like "next time I'll make sure to look for all the ways my opponent can check me" or something more specific like "when a bishop is in the corner sometimes I forget about it, so I need to remember to look at the whole board" stuff like that.
Don't try to find every mistake. Find the biggest one, and again, plan in your head for how you might avoid doing the same type of mistake in the future.
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As for the opening principles and hope chess here's some more info.
Here's one of your games
https://www.chess.com/article/view/the-principles-of-the-opening
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And then for blunder checking, Dan Heisman's idea of "hope chess" is very useful. The idea is you imagine your candidate move as if it's been played, and you look for all of the opponent's threats, checks, and captures to see if you still like your intended move. If you don't do this, you're "hoping" the opponent can not immediately win on the next move.
Everyone checks to see if their candidate move is safe sometimes, but your goal is to do it for 100% of your moves in 100% of your games.
It's tough, and takes time, but raising your consistency in this area will definitely improve your results.
https://www.chess.com/article/view/passive-vs-basic-hope-chess
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