Just a few really basic pointers after looking at some of your games...
1)Try 1e4 or 1d4 instead of 1e3 or 1d3
This opens up lines for your pieces whilst also staking claim to part of the 4 central squares & the central squares d4,e4,d5 & e5 are extremely important in the opening & middlegame.
2)Develop your knights to f3 & c3 early, then mobilise your bishops to squares like c4 or b5 & f4 & g5 if possible.
3)Don't move a pawn more than once in the first few moves. Doing this loses a "tempo" & effectively gives your initiative away.
4)Castle early as this helps link you rooks on the back rank & moves your king away from the centre where it can be vulnerable.
5)Always watch for possible knight moves by your opponent. These are often overlooked when you first start playing, especially a knight fork against your King & Rook.
6)Try to develop a plan & watch for holes in your opponents defence. Don't just respond to moves by your opponent, but even more importantly when you first start playing - watch for attacks by your opponent. I've lost many a game when I first started by simply ignoring my oponents attacks & concentrating on my own most promising moves.
7)Learn the Sicilian defence against white's 1.e4. You can move the game away from white's favourite openings & counter-attack early on.
8)As white, learn the Ruy Lopez & King's Gambit. These can be highly attacking games & the kind of opponents you should start playing will have real problems against these 2.
These are some really basic guidelines (don't forget there are always exceptions to them!) & I'm sure there are many, many more that I've missed, but hope that helps!