Tomato Questions

The curly leaves are nothing unusual, toms quite often do this when they are growing fast - yours look nice and healthy I don't think you have anything to worry about. They will uncurl as the plant grows, it's usually just the new top growth that does that.

You are right, the sideshoot is the branch going straight up in your photo. They always grow just above the join of a leaf with the main stem. Its got quite big for a sideshoot and yes if you leave it long enough it will get flowers and will produce fruit. Looks like you have nipped out most of the lower sideshoots already. Just make sure that you don't nip out the topmost growing tip just yet (wait until they have 4 to 6 trusses, i.e. branches with toms on them before snipping out the top) . If you do a search on "side shoot" you will find various advice on here, I always nip off the sideshoots, but a few don't and get good crops as well. What variety of tomato is it?

 

BTW you have some pretty big grow bags :thumb: in your garden (3rd picture) what are they for?