You will finally be able to realize your dream as a Pokemon Trainer in Pokemon Go. Explore areas and encounter Pokemon to increase your trainer level in-game. Increasing your level will allow you to encounter stronger Pokemon and gain access to better items at PokeStops.
Players will be able to customize their trainer's look. At this time, there are a total of 52 items that can be used to customize appearance.
As stated by the official Pokemon website, Pokemon trainers can be leveled up. At this time it appears to be a max level cap of 50.