I would highly recommend the book Elementary Principles of Philosophy by Georges Politzer which you can find for free on the Foreign Languages Press website under foundations. It is an introduction written for a general audience that will give you a solid base from which to approach other philosophical texts. I'd also really recommend getting a solid grasp of dialectical and historical materialism before trying to dive into other philosophies. Marx laid out the foundations of a scientific approach to understanding the world in all of its aspects. If you understand how to analyze things through a Marxist lens you will be able to cut through a lot of bourgeoise, metaphysical, idealist etc. philosophy which is interesting historically but otherwise useless, or even harmful, if used as a basis for practice.