highlights-of-the-lowlife:

Your boss is not your friend. Your boss is not someone you can trust. Your relationship with your boss needs to be entirely professional.

• Do not do your boss favours. No working for free. No doing unreasonable duties. No working outside the hours you state as available.
• Do not say anything to your boss. About anything. Keep it work related. They will only use personal information against you.
• Know your rights. Know the laws. Your boss will come at you trying to get you to quit like its a favour to you. Its usually because they can’t legally fire you.
• Be wary around your coworkers. Some will have no problem passing things along to your boss. Such as your mental health or financial standing
• Never offer to pay for anything lost, stolen or broken. Especially if money is missing from the till.
• Demand safe working conditions.

Your boss is only there to exploit your labour for profit. Unfortunately you need that labour to sustain yourself. Just be careful.