When you paint over painted walls do you need to use primer paint first? I have been told if you don’t the paint will not stick. Is this true? Because it would be cheaper if I don’t use primer or two coats of paint so I can budget for my

We have just painted the siding a dark moss brown and have lighter brick with salmon and light brown/tan tones. We did the trim in a cement/off white color around the windows. New roof will be a color called resawn shake, which has dark and light browns flecked with a