Toka plum pruning and possible disease?

I planted a Toka plum last summer. It did ok, and came back this spring. I am hoping to get some advice on pruning. Most of its lower branches are only growing from one side , and the other is flat. I read that open center is the best for these, but I can’t figure out how I would do that with this tree. Also, I see a “sore” on the bark, about 3/4 of the way up. I don’t see any wetness or oozing, so hoping it’s ok. If not, I would have to cut off the upper part at the main trunk. Any pointers or info is appreciated!

Cut off those four or five lower branches. That will even it for now and in the future new branches will be popping up everywhere. Good chance those branches would have been sagging on the ground later with a fruit load anyway.