Comments on first new game:
You played an excellent opening and early middle game -- nothing really to criticize in the first thirty or so moves. Very nice.
(Ed --

is joseki and fine for B. In fact, W sometimes answers at F15 rather than E14 to avoid a pushing contest. This is a very big point for W also if B plays elsewhere, so it is worth a full move in the opening.)
I would answer

at Q7, just to take more territory. Note that if W draws back to Q9, B can extend to P7, and W cannot cut. Giving W two forcing moves here seems slightly submissive.

is an interesting invasion. At first glance, it looked like an overplay to me, since B has so many forcing moves above, but I cannot see a convincing way to punish it, so maybe it is good. B play through move 39 is nice. Pushing once more on top at H15 should also be sente for B.

looks like a good attack, but

is not consistent and looks awful. After the first move, B is pretty much committed to hane at G10 and fight it out. Other alternatives for

are E10 or F10, but these also lead to complicated fights. If you see no convincing attack, you could play elsewhere and see how the situation develops. Switch to the Q9 fight for example. W will have to be careful in this fight not to give B enough strength to come back and kill the D10 stone.

is an unnecessary defensive move in the middle of a game-deciding battle. If W cuts at E14, B would be happy to give up three stones, taking forcing moves which help a lot in the center fight. Instead of this move, I think I would simply cut at D11 for a large profit. W might fill the ko, but his group would still be subject to attack, and I think B would have a comfortable lead.
B play through move 63 was again very good. This seems like a good place to pause and count the score. Most of the board is settled, so it should be possible to get a reasonably accurate count. I suggest that as a useful exercise as part of your review. If you find that B is comfortably ahead, then it would be prudent to keep the endgame simple.
The invasion

looks hopeless and might be the worst move of the game. In the sequence through move 102, B managed to get away with it, but did not really gain anything for all that effort. And I think with good play, W probably could have killed the invasion, so B was risking a lot. How about simply playing O15 or O16 instead? Let W have some points on top, but take an equal number of points along the right side. Push once at H15 first. W really does not get very many points on top and would actually end up over-concentrated.
:b103: is an interesting invasion and may actually work, but I question its necessity. Again, I would count the score first, before embarking on something this complicated. But the continuation to 112 was very good for B, so I cannot really criticize the invasion itself. You played well here.
:b113: is trying much too hard. Compared to cutting at D11, B attempts to gain maybe 5 points, but risks losing over 20 points (if W wins the ko after playing D11). Not a good risk-reward scenario. I think I would call this the losing move.
B made a few mistakes during and after the ko fight. Of course, looking at the outcome, it would be better to ignore :w140: than :w146:. After the disaster up to :w150:, B continued with a few bad knee-jerk responses. On review, I am sure you can see that the exchange 151-152 is horrible for B, and the next few moves also just help W. Even at this late stage, if B played to give up those stones on as small a scale as possible, say with forcing moves around J6, the result might be close.
All in all, this was a pretty good game for B. You played many really nice moves, did a good job of reading out most of the fights, and lost just because of a few lapses in judgment. When the game reaches a pause in the fighting, or a strategy decision point of some sort, I really recommend taking a few minutes to estimate the score, in order to help guide your strategy.