With that many flats, and then a blowout just airing it up, I suspect one of three things is happening. Either you have a small wire or thorn stuck in the tire, you need better rim tape, or you're pinching the tube under the tire. For the first, rub a soft cloth around the inside of the tire and see if it catches anywhere. If you're pinching the tube, try putting the tire on without levers, then after partially airing it up check around the rim looking at the bead, if it's not straight or it's pushed out then the tube could be trapped underneath it and it will blow with too much pressure or shortly after you start riding it. Deflate and push the tire in to set the bead better if necessary then inflate again.