This shouldn't be that difficult. Being where you are, I'm not familiar with your solder and flux brands, so there may be an issue with your supplies. Perhaps you're doing this correctly and your flux is just burning at a temperature lower than your solder needs to flow. Asking a local plumbing supply where you are may clear up any issue with your material.
Regarding cleaning, do not skimp on this stage. Everything you have read about cleaning pipe is not an exaggeration. Your pipe must be thoroughly abraded with sandpaper, a stiff wire brush, or steel wool so the copper shines like gold - inside and out before applying flux.
Here in the States, most amateurs use a typical propane torch which works fine for 1/2" and 3/4" pipes. For larger pipes, MAPP gas is an option as well, but no matter what heat source you are using, it's very important not to scorch the pipe and flux, or the joints will need to be disassembled and *re-cleaned* with abrasives.
This is a very short video that shows what properly heated pipes and solder flow looks like. You don't need to wipe after you make your joint - that's pretty much for show.
Good luck!
John