Inzer economy is good starter belt but hard to get used to for those who never used a power-lifting belt. Very stiff at first, needs to be broken in, also double prong belts are hard to put on and harder to take off, really sucks if its too tight and you can't breathe good to take off.
Crain's belt's look very good, I highly recommend Single Prong if possible with any belt, just easier = better.
1st belt should be relatively cheap but good quality 30-60$ worth. You don't want to invest too much if you don't know what is best for you.Most good belts are made from the combination of leather and suede, making sure they last long. You don't want no cheap nike belt, or valeo belt. IMO even Schiek belts are crap for their price compared to the brands I listed.
Lever belts are very comfortable and easy to put on and off, but a pain to unscrew and re-screw to adjust weight, so good for someone with a steady weight pattern, or for specific lifts that the size is set just right.
Taper belts are good for bodybuilder types who are used to regular belts, but need extra support. Elite Fts has a decent one I own but I like powerlifting belts better. Tapper belts allow a bit more breathing room and a bit more mobility.
8mm vs 13mm is just a matter of thickness, the bigger number being thicker obviously.