Part time / Full Time Contracts?

Got back into FM this year, downloaded a league expansion and managed Sutton Coldfield to a promotion, from 10th tier to 9th. Got a little question though, to do with the contracts. At the moment, everyone is on a pay as you play non-contract. Is there a way to offer them a part-time or full-time contract or do I have to be promoted again? Without them I often get my players leaving, plus hard to keep a tab on the wages.

You need to be professional for contracts, iirc