In need of safety glasses, but I wear eyeglasses what should I look for?

Easy, prescription safety glasses. Wore them for years before getting lasik. They are exactly like regular glasses but with safety lenses and clip on side shields. You can just remove the side shield when not at work

My Rx glasses are “minimalist” enough that most cheapo safety glasses fit well enough over them (the cooler, more streamlined styles not so much). If you wear bulkier frames, you may need to go to safety glasses specifically made to fit around Rx glasses. Home Depot sells these.

Prescription safety glasses will be the most comfortable. Wearing regular glasses under safety glasses may be fine for a short period of time but will get annoying very quickly.

You should be able to find ones that will fit over your glasses easily. Find out if there is a specific safety standard that they need to meet before you buy; if anything will do, you should be able to find some cheap at a hardware store or a college bookstore. Try them on and make sure they’re comfortable.

I worked at a place that required safety goggles. They fit over my normal glasses but were really uncomfortable. Luckily the company I worked for had a deal with Shopko and I was able to walk in and say I need prescription goggles and that I worked for Advanced Power Technology and they just made them without any billing hassle.

And these were big goggles too since we had to deal with a lot of open containers of skin burning and eye-destroying chemicals.

@dappled_leaves gives the only sensible answer here. You can’t buy Rx glasses for training.
ASK. I bet the glasses required are provided or reasonable.

If your company doesn’t provide them (they should in my opinion, most companies I have worked for provide safety equipment like waist belts for lifting, ear plugs, and even safety glasses) then try on a few over your glasses at a hardware store. Remember to try looking down and up and not just straight forward when you try them on. Once you feel confident this job is a keeper then you can eventually invest in a prescription pair for better comfort and simplicity.

Try asking what the company recommends. Likely you will find that they provide basic coverage and likely have a program such as @johnpowell describes once you’re fully qualified/permanent.

The problem with over-the-Rx protection is that it either doesn’t fit tightly enough, or it fits so tightly that your glasses fog up. You’ll likely also need gloves and safety shoes. Hearing protection. Possibly hairnet and hardhat. It’s difficult if not impossible for a company to require that stuff without providing it. If you have or receive (or can access on-line) an employee handbook, look for PPE, or Personal Protective Equipment.