Checking a mask is easy. Just get the proper punch and make sure it holds up.
As for the rest: it’s just heavy cloth. That means it’s going to be fine as long as there aren’t and obvious rips/worn areas. Fencing is really very safe, even with used equipment. Schools routinely use the same equipment for 15 years on end, and nobody ever gets hurt. The only thing is to make sure you have a good quality blade with no kinks or obvious stress points. A broken blade is dangerous. I worked as an armorer for my college team for a couple years, and the only piece of equipment that couldn’t be repaired and used was a broken blade.
Ask around at clubs, and buy the cheapest gear you can find that still fits and isn’t obviously worn (if you don’t mind somebody else’s sweat). And then invest in two good blades–one electric and one practice. It will save your sanity if you don’t have to repair broken epees (and especially foils) all the time. Also, if you get a lame, check to make sure it’s conductive all over. If it isn’t, and the price is right, get them to gently wash it with some slightly soapy water, and test it again. If it isn’t perfect, don’t get it; you’ll go nuts trying to repair it.