The people who commented before are right on the basics, but there's a detail worth considering. When you're just starting out, what matters most is that the board lets you practice without getting frustrated, so brands like Element, Santa Cruz, or Toy Machine work perfectly. But beyond the brand, make sure the bearings are decent (not the cheapest ones) because that makes a huge difference in how it feels to ride and how much effort you have to put in.
About electric ones like Evolve: your cousin probably already knows how to skate well, so it makes sense for him. To actually learn the fundamentals you need a traditional board because you have to learn how to push yourself, keep your balance, and feel how it responds under your feet. Electric boards take away that part of the learning and you end up without the basic skills. Once you've got the basics down really well, that's when it makes sense to get into something more sophisticated.
My suggestion is to look for a complete board from one of those brands in the mid-price range - not the cheapest but not premium either. It'll last you fine while you're learning and you won't feel like you wasted money. If you see it really hooks you after a couple months, then you can invest in something better.