If you're new to BP, it's going to be drying/irritating and will burn for the first couple of weeks. The burning will go away after you continue using it. Go lighter on the amount of BP you apply. I probably wouldn't moisturize first because applying the BP immediately to your cleaned skin ensures that is absorbed rather than being added on top of the moisturizer. When you do moisturize after, be generous with it.

Applying moisturizer before treatment really helped me and my flakiness. Most people wont try it because they are scared it will make the BP less effective. For me, it's just as effective. I just wait 20 minutes after moisturizing to apply the bp.