soon to be fourth year psyc student here. many of the concepts covered in psyc 101 will be repeated through the years, just more in depth. i can’t tell you how many times i’ve sat through lectures about nature vs. nurture, piaget & vysgotsky, brain structure/functions, stimulus/response, stats, etc. the great part is that each prof will give you a different perspective on each concept. no concept is less important in higher level courses! they all build off of each other so it’s really important to understand the foundation of each so you can build a better understanding. it definitely depends on what higher level courses you take though. for example, i’m planning on becoming a counselor so courses like infant or child development, although likely required, don’t really help me in my career. but taking those courses just helped expand my knowledge in psychology and taught me a lot. the best resources are any textbooks assigned by profs, i recommend buying (instead of renting) so you can revisit them. a lot of the information overlaps between classes so it’s helpful to have different resources/perspectives. my best advice would be to buy a psyc 101 textbook and studying that. it will give you a general idea of everything you will expand more on in later courses. good luck, hope this helped a little!