Get the skills requirements for barrows gloves out of the way first, then consider doing combat once you've reached around 100 QP. Highest skill requirement is 70 Cooking, everything else is below that. There's no point wasting your time in F2p splashing or doing combat in the Stronghold when you can do about 10 quests and gain a good amount of combat xp.
There's basic bosses that you can do that don't require THAT much effort or requirements like Obor, KBD, Chaos Ele, Crazy Archeologist etc
PVM'ers tend to disregard bossing until they're over 100-110 CB, before that they just do slayer for hours on end per day. Take into consideration slayer tasks (dependent on your level) do rake in a considerably decent amount of profit per hour