Verified answer

J & J = 1 shot. Pfizer and Moderna are 2 shots. After the 1st...21 days Pfizer 2nd shot. Moderna 30 days for 2nd shot.

For Moderna, they recommend getting the shots 4 weeks apart, which is the way they did it where I live.

#2 was a doozy though!  Many people reacted to it, mostly by staying in bed for a day.  Still worth it though.

Go to your CDC site.  All this information will be there.