Although there are many people who do use resin on glass, and regularly, please be aware there are potential risks. Resin and glass do not expand and contract the same, so this can potentially cause issues.
Temperature changes can cause the expansion and contraction to occur at any time. Sometimes a piece will be fine for many many months, but it can potentially crack even up to a year later. If the piece is smaller and not exposed to temperature changes, it might never be an issue. I have created on small 8 x 8" glass sheets, that have been fine for a few years so far, but they also have not been exposed to any temperature changes or been moved much.
I have seen artists post about making big beautiful resin geode artwork on glass panels, then while transporting it to deliver, it cracked, and in one case unexpectedly exploded in her arms causing cuts. Mirrors have different expansion & contraction then resin as well.
That said, I do see numerous smaller glass dishes, glass ware and wine glasses being decorated with resin quite often, and there seems to be no issues with resin on those smaller applications. It is not dishwasher safe, or microwave safe, and these items with resin applied need to be washed by hand.
Many people do use epoxy resin as an adhesive for glass tiles, and to cover mosaic tables, and it works brilliantly for those projects.
To use resin on glass or plexiglass, it is recommended you lightly sand the edges and area where you'll be applying the resin to give it some tooth for the resin to stick. Otherwise, it is possible the resin may separate from the glass/plexiglass. I do see artists using glass/plexiglass for their resin art, just be aware & prepared it may expand and contract differently when/if exposed to extreme temperature changes.
Resin will stick to many acrylic sheets, but if it is flexible (each brand is a bit different on flexibility too), it may cause the resin to crack or separate. Another thing to keep in mind with acrylic, is if the resin gets too hot during curing or while creating, it could cause the acrylic to warp. Acrylic sheets can bow or bend from the weight of the resin, so you may need to find a way to reinforce the back and/or edges if wanting to hang the art. Also, because there are different types of acrylic sheets, you may need to do a small test to ensure adhesion. If it doesn't you can lightly sand the sheet first to give it some tooth for resin to stick.
Resin does not stick well to waxy items including wax paper. Resin also does not stick to parchment paper, or the shiny side of freezer paper. You can use wax to create a void in your resin charm or casting if required. Pour the resin around the wax, and after cure you can pull the wax away.
Resin does not adhere well to polyethylene plastics, such as plastic paint tarps, garbage or sandwich bags, and the shiny side of tape.
Silicone is often used for moulds, and casting projects since resin does not adhere well to it. However keep in mind, you need 100% silicone. Some projects suggest use of silicone calking, but when you purchase it, it needs to be the non-paintable, clear and 100% silicone type of calking, or you may find resin sticking to it. If the resin is overheated however, it can end up fusing to the silicone, so be cautious to learn how to avoid that.
Resin will stick well to ceramics. If it's a 3d shape, you can use a disposable foam brush, or gloved hands, or some people prefer to use a make up brush as they say it helps to avoid lines.
For using resin on metals, it needs to have some tooth in order for it to stick well and not separate. You'll need to prepare the metal surface by degreasing it, then abrade it, and thoroughly cleaning. You can use 80 grit sandpaper or an angle grinder. For larger areas you can use grit blasting (sand blasting) on the surface. Some aluminum panels already have a brushed finish making it easier for resin to bond to. However, once again, be aware the resin and metals will have different expansion and contraction effects. However, if the surface has been prepared well, the resin should bond well.
Regardless of your substrate being used with any epoxy resin, extreme temperatures aren't great for any epoxy resin pieces, so do try to avoid exposure to those types of elements. Extreme heat can cause many resins to warp/bend or dent at point of contact. Extreme cold such as freezing, could potentially cause cracking/separating/warping of resin or substrate depending on different circumstances.
Epoxy resin adhesives will bond with most all woods (though a primer sealer if often recommended for many types of wood to seal it).
Resin does not bond to Teflon, polyethylene, polypropylene, nylon, or Mylar. It bonds poorly to polyvinyl chloride, acrylic and polycarbonate plastics.
Some artists may sand, &/or use Golden brand GAC-200 for covering glass, tiles, & PVC prior to pouring resin on.
Basically, non porous surfaces will need to be treated before pouring resin to create bonding between them.
For other items not mentioned, If you’re unsure, The only way to tell if an epoxy will bond to a material is to test it.
To Damn off an area in Moulds, you don’t want resin to stick or flow into, there are a few options:
You will need to experiment to see what works for your application.
You can put an HDPE piece cut to size in place, then silicone in place.
You can use silicone (clear & non paintable), or a silicone putty.
You can make a tape dam, and hot glue it in place.
Tuck tape is strong but depending on piece, may be hard to remove. But some artists will just use a strong tape to wrap an area they want to build resin up in, or keep resin away from flowing over.
Use a low temp hot glue, high temp sometimes can ruin the mold's finish.
For small or finicky areas, you maybe could use a wax. Resin won’t stick to wax, and it could be pulled off afterwards. Some jewelry makers use wax to separate a spot where a gem will go for example.