If you don't feel that you are ready for an engagement, DON'T DO IT! Yes, you are correct, you need to get yourself settled, with a job, etc. Good head on your shoulders, don't be pressured into a decision like that, just remember, it's your life, nobody else's. Good luck!
My girlfriend spent last night pressurizing me into giving her a date for our engagement. I'm not even working yet and I believe its important that I should be able to support her first. I'm just 22 years old. Advice?
I think you shouldn't be forced to take such a big decision. Marrying someone is a huge step, especially at your age and especially (as you correctly said) if you do not have a solid job.
You need to be financially stable and independent not only to support your partner, but to support yourself, house expenses and eventually your kids. Finding a good job that you like is also important for your wellbeing and personal establishment and growth.
Find a way to talk to her and be honest. It doesn't mean you do not love her, but there are certain things that you should probably take care about first , before you commit to this. It is completely understandable that you feel uncertain and the best way to solve this is to be open and honest with her. You should get married when you're sure you want to, not when someone else forces you to.
Best of luck!