A: You can use several resources freely without having to login to the NCBI (National Center for Biotechnology Information), specifically PubMed. Just go here: https://www.ncbi.nlm.nih.gov/pubmed
If you want to create a login for the NCBI (to save your references, for example), go the upper right-hand corner of the link above. Click the link, and then click “Register for an NCBI account:”
Once you’ve done that, you just follow the prompts to create your own user account: https://www.ncbi.nlm.nih.gov/account/register/