it's difficult but not impossible. keep on top of the material! I can't stress that enough, if you get behind it is not fun trying to catch up. Don't wait until the last minute for anything, you never know what other tests/projects might spring up and get in the way of that last minute study session you had planned. There will be a lot of weeks were you have multiple tests to study for, but as long as you're organized about it you shouldn't have a huge problem finding time for them all.
working in a pharmacy definitely helped with certain aspects like recognizing medications and it gave me a head start in law but it wasn't really necessary. I had plenty of friends who had not worked at a tech before our first year and they did well.
just stick with it, know what study habits work for you, and have fun with it. definitely don't stress out too much, its not worth it. if you keep a study schedule and don't get behind you'll be fine. Good luck!