I donate blood every 8 weeks, and don't get any money or compensation for it (other than the great feeling that I'll potentially help another human being).
From a lifting perspective, I almost always train the very next day, and although I might notice a slight drop in energy, I always have solid lifts.
Just make sure to wait at least 24 hours before you lift, or else you can risk dislodging the clot and having it get stuck elsewhere (which is very very dangerous). I've seen pictures of lifters who donated blood and then lifted 4-6 hours later, and their entire arm is blue because the clot dislodged and get stuck up in their shoulder.
Schedule your donations on your off days and you'll be golden. Just be smart and wait 24 hours before you go lift.