The best way for you to not get smacked in the face when finding, interacting, and eventually working with a manager is to
familiarise yourself with legal terms. The negotiation stage can be the most bloody part of the legal process - and you need to arm yourself with the right equipment.
When I was working for an agency
drafting proposals for marketing and social media - we would always make it a point to make sure that both parties know 100% what they're getting themselves into. People, sadly, still make the mistake of not reading the fine print. So, before you put your signature on any piece of paper - have someone else (preferably in the legal expertise) review your contract, get second opinions from your friends or family, and THEN - only then, would you commit yourself. That'll save you buckets of tears and sweat.