Why don't I have the appraisal feature in Pokemon Go?

You can only use the appraisal feature if you are a part of a team. The menu option appears in the same context menu where you transfer pokemon.

There are two requirements to unlock the appraisal feature.

1. Choose a team - available at trainer level 5 by visiting a gym.
2. Must be at least trainer level 7.

Even without the appraisal option you can get an estimate by typing in 1-4 and putting a star(*) into the search bar. It will show you all of the Pokémon that fall under each category separately. Also, I recommend downloading an IV application to give you a better look at your Pokémon, it will determine it based on CP and level. But as they said for the in game appraisal option you must choose a team by going to a gym and your character must be at least level 7.