This game was really fun, it was so close at the end but I made a mistake and lost a big group.
I would like to know where I made mistakes especially in the Opening and Middlegame.
In this game I played White, time was 10minutes + 5x30 secs.

Some of your basic shapes are good -- keep studying them. A few ideas:
(Edit: Joaz is right about -- your move is good )

Thanks EdLee! There is a lot I can learn from your comments

I have a question about Black 5: this is the first time I have seen this move, is it posible to invade or reduce it later? Because Black got a large territory in the LL corner at the end of the game.

Most of your game looks a lot stronger than 14K. If someone showed me the kifu and said that white was 8K, I'd have no problem believing it.

16: C11 is big. But Q15/R15 is urgent. It is hard to say which is better. If you at least considered it, that is probably ok at 14K

22: I like your choice here. With apologies to Ed, I think that it is way better than P18. The upper side is cramped, the right side is wide open. If white plays P18, black gets Q16 with more influence toward the open side.

26: As Ed says, this is a bit slow. But I can't say that it is a bad move at all. It is really strong and solid. Just make sure that you use it later and cash in on that strength.

28: Expand off of the strong position.

30: Again, expand from the top.

34: This is your only really bad move of the game. You must play R11 here.

42: He has a small group up against your solid wall. Be agressive. Hane.

46: Here you have reached a turning point in the game. All groups have reached the limits of easy expansion along the sides, and further play along the sides is mostly yose. All groups seem to be reasonably safe (with the possible exception of your left side group.) The major concern now is who can get territory on the center.
Your biggest concern will be that black might combine these last two issues, attacking your left side group and getting central territory. Moves loke F7, F8, E12, and E11 look good for black. To forstall this, I'd play E11 or E6.

48+52: Good.

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To exploit 5, recognize that invasion is possible. If you do invade, he will get outside influence. So I'd sneak along the lower side, getting something aound the G3/J4 area to neutralize his forthcoming influence, then invade with C3.

If he sees your plan as you approach along the lower side, he may defend his corner, but then he is making three moves in a corner when two would be optimal. So he is overconcentrated. Either way, invasion or overconcentration, you benefit.

Anyway, that's the theory. I'll see what Takamiya has to say about exact details, and post later.
EDIT: Takamiya's 'Enclosure Joseki' has nothing on the paticular formation.

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Thanks Joaz that really helps a lot!
Well I am an 8 kyu on KGS but the players on tygem seem to be incredible strong, I also watched a game between 8kyu's on tygem and I think they are weaker then 14-17k players on tygem. Well it could be just my imagination