I love range pures, koing is slightly tougher on them then on a classic 50/60 att pure but they do very fast damage.
Even something like 80 range, 1 defence, 1 prayer and almost nothing for other stats does very good with knifes/crossbows/dbows(+1 worlds) or even just a classic msb.
Range pures are easy, get a bow and arrows and start training . Start on cows and just keep moving up from there. Rock crabs are good once your level 40. The best training wep once you are level 20+ are probably bronze knifes, however idk if they still buy. Fleshcrawlers are good cash but you need food.
Quests aren't a neccesity for range pures which is one of the good things (no countless hours spent on addy gloves or ancients.) 1 pray is optimal and you don't have to do any quests, if you however do want pray for some reason then just make sure you get an accumulator while doing it.
Best way to start would be to make some money (like 1m or something) which will take a few hours, and just start training from there. I would honestly just reccomend sticking to range at the start and ignoring melee/mage. However in the long run you'll most likely get them up if you continue with the pure.