Wanting Chess Advice

Play 1.e4. Then develop your pieces with 2.Nf3 and 3.Bc4, if they cannot get captured there. After that, get castled (0-0). Your king will be safe. Don't move the pawns in front of your king unless you're forced to. Develop your other pieces, for example with d3, Nc3 and Be3/Bg5. See if your opponent leaves a free piece hanging and if so, take it. The value of the pieces is roughly Queen: 9 points, Rooks: 5, bishops and knights 3 and pawns 1. There is so much good advice on this site already. Try searching the forum. Additionally, just look up chess principles for beginners on YouTube. Chess Network is very good at explaining things.

Improving Your Chess - Resources for Beginners and Beyond...
https://www.chess.com/blog/RussBell/improving-your-chess-resources-for-beginners-and-beyond
At one of your rapid games you lost, you played the Barnes opening. You can play this sir you lead 10 wins to 1, but not when you want to improve. Just start out normal like 1.e4 e5 or 1. d4 d5. In that same rapid game you gave up your bishop for no reason. It could be captured for free!
You played against a 700 one and you played the grob. This is a bad opening. Then you gave you rook for a pawn. A rook is 5 points while a pawn is only 1. This is a bad trade.
Just for now. Maybe play normally and don’t play weird openings which hand the center to your opponent

Everyone here is spouting off their own opinions about how to improve. The op should just go to google or youtube to find what they're looking for. This type of question has been asked countless times before.

You have only played a few games so don't be too disheartened that you aren't winning yet. It is normal to lose your first few games when you are first starting.
I agree with @Propeshka start off by watching some videos for beginners on YouTube. That will teach you good principles. There are also many good chess book for beginners that will help.