If you get level up you get a reward, all rewards for level up is showing here:
Level up.xlsx
Tips:
Use an lucky egg if you are going to evolve some pokemons. This lucky egg will give you double XP so you will get level up faster.
If you want to use your lures, it is the best to go and sit down between 2 pokestops, this way of farming is fast and the best way (tip: use an incense while sitting down)
If you are driving a bike and catching pokemons, shake with your hand like you are making a step, if you make a step your egg will break out faster.
Use an pinap berry to get 3 extra candies while catching an pokemon.
Switch on Adventure Sync to hatch your eggs faster. (it makes your battery go faster down)
Take photos from already caught pokemons, sometimes it will give you the chance to catch a pokemon like pikachu.
Catch Ditto: Ditto eventually found its way out into the world, hiding as Pidgy, Ratatta, Zubat, and Magikarp. With Gen 2, Ditto also learned to hide as Sentra, Yanma, and Hoothoot, and Gen 3, as Zigzagoon and Taillow. Then, when Shiny Magikarp appeared, Ditto Magikarp disappeared. Now, just as Ditto has become a prerequisite for finding the mythical Mew, Ditto has added Ghastly, Whismur, Gulpin, Mankey, and Remoraid to its repertoire as well, and now Meltan as well.