I did decorative painting back in the ‘80’s, early 90’s. alwAys seal the wood before painting. Sand the sealer smooth and repeat until your are happy with it and it’s ready to paint.
I painted pine. Inexpensive and sands nice.
I take my finished pieces to Hobby Lobby or Michael’s, (whichever is having a sale) and get the frames there. There is usually someone in the frames department to assist, I can also get them matted. The frames are usually buy one, get one 50% off.