I have a model I’ve created, but I need help figuring out how to make the section that goes between the two blue faces, and I need the angle to be smooth.
Use loft with tangency or with guide rails. Or sweep.
when i try to do that, i says that the body wouldn`t be valid
What exactly?
If you can share the model I will show you how to deal with it.
I can show you an example, but that doesn’t mean it will work in your case.
tell me if that works for you
now it should work
how did you make that look so easy, make me feel a little stupid
Practice.
Sorry 
need to learn the program a little more
thank you sooooo much