Once I was asked to start working on an app in a new domain, I had never worked in that domain and without good enough knowledge, working on that app would be crazy. The first 2 days in it and I realized, there has to be some systematic way of going about it.

I brought it up in the next weekly meeting, asked for a resource (book, session by colleague, video anything) from the team already working on it. They recommended a book and I explained that I need to work through the book while correlating the app with the book and working on bugs/features, all the same time while explicitly stating that I need some time/guidance to be up and running.

That was taken very positively and in a few weeks, I was productive as per/more than the expectations, while following the steps outlined.

Don't worry, be pro-active, ask, make a plan with the team and follow it. The more you do nothing about it, the worse it might get. Best.