I don't know what to do to get my levels up fast? I think it's missions but is Octafari Distress the best thing to do if you want to level fast or what? Im rank 35.

To be perfectly honest, at that rank missions are the way to go for leveling. Unless you log on to find a rare NPC like a TO Troop Carrier or RSL labpod or experimenter, something like that, don't even bother with NPCs. You can dabble in PvP if you have a well built ship too, as you can get a decent xp/erg ratio and PvP is A LOT easier at low levels (so get your red badges early).

BUT... Unless you have an insanely high resource production, do not try to level fast. Take it nice and gentle. The faster you rank up (especially at lower levels) the faster you will rank beyond your tech. Go slow, do your research and build a strong ship. If you have a stronger ship than everyone else at your level, you'll take less beatings and you'll be in a better position to farm NPCs for extra goodies when you hit around level 100.

thank you mate Im very gratful for high ranks like you helping me out

i always recommend PVP at that rank... badges are easily obtainable, easier competition and retaliation isnt as bad. if you decide you dont like PVP then there is no ground lost, infact you get the "know how" earlier than most everybody wins by Perto's book

The other PvP advantage is most people who drop out of the game, do so before rank 50.
Inactive people = full productions to farm and very little retaliation.