Hi Maria, and welcome to the forum.

First of all many of us cut our own bezel strip from 4.0mm fine silver sheet using a saw. This is less prone to melt, and you an cut only what you need.
Use hard strip solder, which has been thinned out, and cut into tiny snips.
For flux you can use borax, but some use Auflux liquid, which is less prone to bubble.
Don't be in a hurry, but use your torch with the air hole slightly closed, and gently heat the whole of the bezel, moving the torch around until the solder flows.
Work in a darkened area of your room, so that you can quickly spot overheating. It should stay just a dull red.

To make balls, make a little hollow in your soldering brick, rub up your metal with sandpaper, and place a snip with flux into the hollow. As above, do not hurry, but apply gentle heat until the metal reddens and balls up. Dennis.