Hello! It is my first time on this platform and I have been wanting to know the policies and process on how I can publish my research papers and also have them peer-reviewed. Thank you very much.
Please note that ResearchGate is not a publisher and not a journal, you cannot "publish" a paper here. It is a platform for papers published in journals, or to present unpublished texts, data etc. See also "Is ResearchGate a publisher?" in https://help.researchgate.net/hc/en-us/articles/14292596164753. You should look for a journal in your field of research and submit your paper there. See also the following discussions for recommendations:
I agree with Dr Wolfgang R. Dick that if it is peer-review that you are seeking, you may need to obtain this from submitting your work/manuscript to such a journal as RG does not fulfil this function.