I personally work for more than 20 years as dev and really hate to see myself as senior. I think I am more of a Veteran. I only have more practice and survived more projects. What I am trying to say is, give yourself time. Nobody starts out and knows everything. And even if you have experience, there is always a bigger fish. Simply because the topics are too complex to know them all.
If you have trouble because the clients do not support native oauth, you can try to use a auth dameon like https://github.com/ltratt/pizauth