Does anyone have a beginners guide on learning to etch on glass?

It is not technically hard, but it can be messy. I would start with a pane of glass (like from an cheap frame) or a mirror square, cheap, from a home improvement store, just to get the process down. You can etch glass, windows, framed, glassware or mirror, which is glass... either permanently or with a frosted spray paint.

Not to be attempted in a hurry, or without Patience or the needed supplies and tools... but it can give you some great results when done well.

Check out Pinterest, or Youtube for how to do it.

Google it.

ive seen many etched items, it can be done on just about any glass item. the etching cream is used with a stencil for the design.

Yes you can stencil most anything glass (bottles, glasses, window panes, large wall mirrors, bathroom shower doors, etc.) and mirror. I know of 2 ways: stencil cream and sand. You paint the object either freehand or using a stencil. The cream acts pretty fast. The same is true for the glass, but you use VERY fine sand along with canned air. If you are doing many you have to buy extra cans of air. (we didn't buy it all from Michael's, like a hardware store or an office supply store. It is what you use to get dust, etc. that falls in the keys of your computer.( You can buy what is needed in Michael's I know for sure and imagine other craft stores have it and Amazon https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=canned+air) We etched 100 champagne flutes for our wedding. It takes much more time than the cream. The stencil didn't work well with the cream because we couldn't keep it from going under the stencil.

I have done dozens of etched beer mugs using Armour Etch cream and clear contact paper from the dollar store. I give them as gifts for weddings and Christmas. If you are doing a lot of items you may need multiple stencils but each of my projects was one of a kind. Your design will only be as good as the clean cuts and good adhesion of your stencil. Good luck! Another option is precision cut sticky vinyl using a Silhouette machine. We did 100 glasses for an anniversary party with fancy script font and they looked gorgeous. So far they've survived multiple dishwasher trips, too.