Hello!
How tall should I let this new tree get before I start pruning?

What do you want the tree to become in the future? What style and how high.

This is a blank canvas and you are the artist.

In any style you shoose there are several years before any real styling can be done. The only tasks worth doing on this young seedlings is wire the trunk and cut tap root.

I hope you moved it indoors for photo only? Cherry trees belongs outdoors.

Where in the world are you? Cherrys should be in full leafs now in most of the northern hemisphere.

Does that pot have drainage holes?

Interesting pot.

A better question is how thick the trunk should be.

In both cases, the answer is as thick/tall as you want it to be.

We are growing it indoors but have it under grow lights. Live in the state of Oklahoma in the US. We got this from Etsy it had full leaves when we got it but they were dried up and they fell off. The pot does have drainage holes. How do I wire the trunk?

mattw77777 wrote:

We are growing it indoors but have it under grow lights. Live in the state of Oklahoma in the US. We got this from Etsy it had full leaves when we got it but they were dried up and they fell off. The pot does have drainage holes. How do I wire the trunk?

The first thing to do is keep it alive. In Oklahoma it should be outside all year. It wants wind, full sun, fresh air, humidity higher than indoors, and that is not what it gets indoors.

Move it outdoors and see if it grows leaves and will live.