Pruning a small Zwetschge (Prune Plum) after i forgot to prune it after planting.

Hi Permies,

i have a problem and i hope you can help solve it.
This Prune Plume i planted last fall without pruning it. (First mistake, i learned a couple of days ago)

Now it was already in bloom and is leaving out and i am hestitant if and how to cut.
It also has a second leader which is longer then the 1st.

I already cut the small crossing branch on the first leader.

Edit. I forgot to give sundirections: The white wall behind the Zwetschge is shading in the morning (East). (can i say the wall is westfacing?)
Edit2: I also forgot to mention: I'm not plannig to live here very long max 2-3 years. After that i would like to take the tree with me, thats also thea reason why i planted it so close to the wall.

What would you advise? Can i still cut now? (I'm in Germany ~8b)

Thank you!