Can I donate blood if I have hepatitis a?

Depends on Age. Per the cdc, if you acquired hepatitis a before the age of 11, you can still donate. However, if you had hepatitis a after the age of 11, then no, you cannot donate blood. Check with your local blood donation center/bank to be sure.
Hep A. Is usually an acute illness that reverses without consequence to blood donation as opposed to b & c. Come back next year after you get well.

Related Questions

Can I donate blood if I have hepatitis b?

No. That is an absolute contraindication. There are pre-screening questions that need to be answered prior to donating. They of course also check donated blood for usual infections such as hep b, hep c and hiv. Since you already know that you have hep b, I wouldn't even bother.