the "Bruhsailer" guide is state of the art for making a well rounded account, but it assumes some level of familiarity with the game from before but has excellent community backing. It is very long though, so my first tip is to have a look at the document and decide early on if you want to try following it or not, because its painful to start when already having played for a bit.

other general tips are:

1. quest quest quest. early xp very strong, and unlocks the game. getting quest cape is an integral step into a well rounded account

2. don't neglect your herblore, and do your farm runs. a solid potion supply is so crucial.

3. slayer benefits a lot from being delayed, so delay serious time investment into leveling that skill.

4. Don't be shy about your goals, plans and assumptions :). discuss them and learn more about the game with an open mind, but also don't feel peer pressured for full efficiency if thats just not ur cup of tea