My games: Need Help

I would like to share with you in this thread games i played in the hope that you'll give me some advice or pintpoint me particular weaknesses.
I'm a beginner and just started to take chess seriously 2-3 weeks ago. So i'm still learning the principles.

I'll post more games from time to time so i won't have to open a new thread for every new game :)

Thanks a lot for any response

Your principles arent terrible for a beginner.  Certainly there are things we could point out to you that would help there.  However, the big thing I'm seeing is that your making a lot of blunders and dropping material for free.  All the principles in the world wont fix that.

You need tactics practice.  Use the tactics trainer here if you are a premium member, or go to chesstempo.com if not.  Chesstempo.com does have a premium membership too, but the totally free membership is EXCELLENT.  Make sure to register and dont do problems as an unregistered member - registration (free) gives you a rating, and the problems automatically adjust to how you are doing.  Its actually quite fun.  Depending on my mood, I sometimes enjoy it more than playing.  

One idea that might be helpful is that chess is not a one-move game. Getting into the habit of thinking "if I move here, he'll move there and then I can or need to..."

Thinking out two or three moves is probably a good place for you to aim for.

For instance, there's a rule of thumb that you don't push the B's out to the 5th rank early unless you already have a plan for it. In the first game 5. Bb5 is premature unless you're ready to trade it because ...a6 and ...b5 gains for Black while pushing you around and your B didn't gain anything anyway.

Later sort of the same with 8. Bg5 which was pushed back easily and its blocked diagonal ended badly. Examples like these might not be too hard to foresee after you get used to the planned move sequence process.

In the third game, though 5. Bd3 isn't necessarily a bust but after realizing there's a weakness you need to take some sort of remedial action thinking "if I move here he can do this and then I have to do this etc."

Obviously your plan in the game wasn't optimal. It might be worth playing over that part a few times (thinking out a couple of moves) with another player to find improvements.

A last suggestion is to play OTB or online games with at least 15 min per player, preferably longer, until you feel comfortable looking ahead a number of moves. IMO Blitz and Rapid can be fun but they'll never allow you to get chess sight out far enough to make major improvements.

What's really interesting on you tube or somewhere is watching the GM's play Blitz. Very often early in the game they spend a lot of time not moving but thinking. Then they both shoot off a series of moves then spend more time thinking. That kind of timing may be ultimately what you're looking for.