It looks like cestrum nocturnum - Night Blooming Jasmine.

See those dark green veins in light green foliage? That's a sign of magnesium deficiency. Put a cup of epsom salts around it and water in well.

Wow... Thank you both for the insightful comments, I am trying SO hard to make this garden work. I have BLACK thumbs! My dear friend hauled in a truckload of mushroom soil for me & mysterious things started to grow. I certainly will add Epsom salts to my stealthy night blooming jasmine plant. Also working against me....this seems the worst spot for a garden, morning shade & afternoon sun. Full sun during the summer. However, I am such a horrible gardener that I dare not locate this is my front yard where the conditions seem to be optimal. I'm trying...I really am.

It is a deficient avocado seedling, Persea americana. Seedling trees can take many years before they bear fruit. It can also get large so consider the location and if there is room.

Oh! I was hoping it was an avocado plant! How large are we talking? It's about 10' from my house. I probably should move it, to be safe. Deficient in magnesium, as dirty gardener mentioned? I'll add the Epsom salts asap. Thank you all again for your help.

Since it is a seedling plant it can easily get 30-40ft. I would give it at least 20ft of space from the house. Since it is a seedling it will also be a more tender, cold sensitive tree and seedlings can take many years before they bear.

"Many years" meaning 7-15, and it may never bear, but it's worth a try. Look at the trunk. Does it have a spot that looks like a graft ring -- a definite delineation between the top and bottom of the trunk? It should be a few inches up from the bottom. If it does, you're in luck. If not, yes, many years to bear, but a nice shade tree in the meantime. You can keep it pruned back to keep it from getting too large.