It is okay to do it the next day. It would serve as active restoration. Just keep the sessions short until you get used to it. Try maybe 5-8 3 min rounds at first. If you lift in the morning, you could even do it the same day.
Hitting a bag is great for conditioning. I found it handy to have around to bash when I missed a lift;)
As a side, the bag is great for a DE warmup. Later.