There's no need to panic, you have lots of choices. Don't rush into a decision - think carefully and talk to your parents and teachers about your options.
You can resit this will not automatically improve your grade though. If you only need to resit a few, you might be able to do it alongside AS levels, Highers or BTECS. Have an honest chat with your teachers before resitting. Many people do much better when they resit, but if your teacher doesn't think you can improve it might not be worth it. It can also be lonely if all your mates are going on to do other things.
Can I still do AS levels?
It depends how low your grades are. Talk to the college ask if they'll accept you with lower grades.
If they say no, contact other colleges to see if you can study there instead. Alternatively, consider taking a vocational course as they have lower entry requirements.
Can I get a job?
Yes, but find out if your results will get you the sort of job you want. If not, can you work your way up? If you have the right attitude and personality many employers will offer you training. An alternative is an apprenticeship, which will let you learn while you earn.