I don't get any notification sound unless I have an ongoing text open

I would like to change my notifications back to where I can select which location I want to pick my notification from instead of using out of the same folder. I have other notifications I would like to select and use.

They already have this. Go to the main screen as if you're doing a batch delete of multiple senders' threads. Select the same way (can select just one). Go up to top right corner. Click the dots. Select the per contact option. Once there, select the notifications option. Change sound, flash color, icon color etc there. :-)