No, 38 is not too young. Sure, you'll get better as you get older, but there's no reason not to start now. If it's a software startup, you'll want a good codebase in place now before your kids get old enough to hack on it.
P.S. You put "am I too old" in the title. You might be able to get one of the moderators to fix that typo.
P.S. You put "am I too old" in the title. You might be able to get one of the moderators to fix that typo.