Hi and congratulations for receiving your RC.
I can tell you from my experience that inthe xase of Surinder Singh, applying for the EU settlement scheme is not a straightforward process and that you must apply asap as you are required to submit a paper application and HO will take some 6 months to confirm your status (and yes, we applied and we are still waiting).
You must call the EU settlement centre (or email them) and ask for the forms. They will ask you for your details and your card number.
You will receive a personalised form in the post. Complete the form (some 50 pages - but you will not need to fill in all of it, just the questions that are applicable to you) and send it back with the documents needed.
Here is a link that explains it all (scroll down to the Surinder Singh part)
https://www.gov.uk/settled-status-eu-ci ... ss-citizen
Good luck