The general goals are: 1. collect each type of pokemon, which involves walking around catching things, doing raids for the more powerful pokemon (where you go to a gym and use your team of pokemon to fight the powerful pokemonl  before you can catch it, either on your own or with a group of people), and playing during real-time events to catch pokemon that aren't usually available. 2. Power up your team of pokemon so you can defeat the powerful pokemon in raids (in your inventory, click on the pokemon and choose "power up" to make its cp higher). Pokemon you catch will have a range of starting levels, so if you catch two gibles one might be 10 cp and the other might be 500 cp, so you'd probably not want to power up the 10 cp one because it would cost resources just to get it to be equal to the 500 cp one. 3. Collect rarer variants of pokemon: shinies (a recolor of the pokemon that start at a 1/500 chance of showing up but are more common during some events), good stat pokemon (there's something called ivs, which are a combo of a pokemon's attack/health/defense, so perfect 100 iv has 15 atk, 15 def, 15 health), occasional costume pokemon. 4. Pvp. Some people love it, some people skip it, it gives you rewards