I just finished the Ridinghall L1 and it says that I can now train pets up to L.10.  How do I do that?  I have looked at various pets but don't see any button or such to send them to training.  

Help!

Open the pets page and make sure it says active.

If it is a baby, pregnant, questing, or crafting you wont see it.

Now right next to the level of your pet should be a bottom that says train, that's the one you need to press.

I recommend you go exploring with your pet first and use all the energy, cause training doesn't require energy. That way you reduce the cost of the training.

Good luck!

By the way, you can train only 3 pets at the time. And that the pet is not level 10 or higher.

I finally found it!  Thanks so much.

"By the way, you can train only 3 pets at the time."

This is of course true, I just wanted to add that this also changes when you upgrade the building. At level 5 Ridinghall, you can train pets up to level 50 and have up to 20 pets in training at once! :)