Not enough information...nevertheless: two blowouts indicates to me that all tires are shot. Too old, too many miles, not enough air either now/in the past/both...possible causes are endless. The fact that you've had TWO blowouts, though, indicates at least to me that whatever the problem is, it's across the board and affecting every wheel on the rig.
Probably best to replace them and learn the maintenance ropes before doing the cross country trip with your family you posted about earlier!
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