The book "Approaching the Buddhist Path" is a solid foundation. It comes with a free 70+ hours of lectures by Venerable Thubten Chodron: https://www.youtube.com/watch?v=8DNQHTMMDNE&list=PL8DRNsjySiiaJrZpDIGiCLIQBT62K6YxL
I can also recommend a course but I'm not sure if it fits here.