London system for white
openings to learn best as a beginner?

btw when i play with computer why is my elo shown 1150 whereas my elo in live chess is around 600-700
@1
"I’m 600" ++ Then do not worry about openings, worry about blunder checking.
You do not win or lose because of the opening, but because of tactical mistakes.
"it’s time I learn some actual openings" ++ No, it is not.
"trying to take the center" ++ That is the essence of opening play.
"I need some simple stuff" ++ As black defend 1 e4 e5 and 1 d4 d5, as white open 1 e4.
"gambits" ++ Most gambits are unsound.
"king’s" ++ gambit is dubious
"queen’s" ++ gambit is sound, but hard to play correctly
"Are they good starting positions for a beginner?"
++ No. Better 1 e4 e5 2 Nf3: develops a piece, makes no weakness

You are about 1000 rating points lower from the level you could consider studying openings to improve your play.

I believe principles are more important than opens at this level.
So my recommendation would be to focus on 1 or 2 openings and then focus on opening principles.
For white:
Italian Game, Scotch, London System (Although you may face the Indian game)
For Black:
Either focus on responding solid with e5/d5 or play something solid like the Caro Kann
Best of luck my friend

You can start studying openings but you won't play them at your level. Your opponent doesn't know them either. It takes two to play theory.
Taking the center is good!
Ask yourself two questions when you make opening moves:
A) does where I put the peice help me and actually do something in the position?
B) Am I wasting time?

I would just play something normal like the italian. But with two new concepts: 1. to bring the queen's knight to the kingside, and 2. to play c3 and prepare d4.

I think the queens gambit is the way to go for beginners since you will learn the classical chess principles as you play it. You already know you need to learn tactics, you're not really in danger of neglecting that since it is just unavoidable and will always be obvious, but you also need to learn about positional play.
Also, gambits, like the king’s and queen’s, seem good. Are they good starting positions for a beginner?