http://iscoresports.com/

I missed a batter in th first inning is there a way to fix it at the start of second inning when I noticed it?

only choice at that point would be to undo back to the missed batter.

No way to do that because it was a long inning where we scored 6 runs

The other thing to do at that point is to continue to score the at bats as you see them (you will be off a player the remainder of the game, but just get the sequences captured). Then use this pitch-by-pitch sequence to re-score the game afterwards.