Employer set up a SEP-IRA for me…. Next steps?

Hi, very clueless young man here… I’m very confused on how a SEP-IRA is supposed to work – Do I, the employee, need to take any additional steps? Do I fund the account/does it come out of my paycheck? My employer literally just set me up with it and shooed me away.

I was also in the process of opening a ROTH-IRA myself – can I or should I still do so?