Don’t, glassblowing is a very frustrating art to learn. Joining tubes will cockle up at the drop of a hat.

If you must, try a book Creative Glassblowing by James Hammesfarh and Clair Stong published by Scientific American.

Book has details of air/gas venturis and air/gas burners (glassfires). Plenty of examples on the web. Be prepared for a lot of experiments and failures.

I did try making my own glassfires – propane/air – possible but tricky. A glass lathe can be made from plastic sheet with aluminium chucks, a leadscrew to bring the two together. Drive the chucks with two stepper motors at the same speed. I Tried and found my hookup too flimsy and while I was concentrating on the joint I was alarmed to find an almighty bulge in one of the silicone gas hoses. Be careful.

I made a fairly useful fires using butane pencil torches with the back chopped off and a hose fitting JB Welded in.  Probably not ‘gas safe’.

For borosilicate/pyrex you need oxygen, gas/air does not quite cut it. Assorted ways to use ex medical concentrators or the usual gas bottles.

Have fun.

Good glass blowing torches for lab work usually have multiple jets, although hand held touches are less complex.  As discussed appropriate glasses are essential to block out sodium glare.  For forming graphite tipped tools are useful.  Never used a glass lathe but have seen them bit like a wood lathe with two hedstocks and circular burners, mostly used for big work.  Anealing is essential, but to a small degree this can be done using a diffuse flame on odd jobs.  Joining glass tube is easy provided you learn to rotate the tubes in the same direction and speed best done on most by hand especially where tubes are different diameters.  You will need corks for sealing tubes not sure if there are videos arround on scientific glass blowing?  Its fun a bit like gas welding but get used to picking up the hot end by mistake, buring your lips by mistaking the hot end.  Unburnt gas getting caught in the tube and exploding when you increase the pressure by blowing into the tube to mix the gas is an interesting experiance but not harmful.  If you want any further tips feel free to pm me and we can sort out a video call.