Imo the 3 classes you have are the best suited for any mele cp you might want to begin in future. Playing active support classes are always welcome on clans and cps, specially on late game.
Although at first you wont meet many ppl since sv is old and you ll lack dmg, the more you progress the more you should engage with other ppl and clans to form a full functioning daily party. And thats the core of your route to take i think. Complete the dmg and tankiness you lack with friends and you ll progress much easier.
After lv 20 i recommend you to get a mid bow d for each of you, you might have the chance to join raid boss parties, which are the fastest way to lvl up. Even if you are mages and dont have complete set of buffs, just adding your bow dmg is enough for many pts to take you. At 25+ you should do moon knight armor quest. One of the few quests that are worth doing besides class change quests. The other ones worth doing are at 58+ in loa for getting enchants. Quest name is "Whisper of dreams". For any info related to anything check l2 wiki classic, 90% of whats wrote there is here, rest is more updated content we still dont have
As a side note, in classic debuffs have a much better land rates than interlude, so pvp ll be interesting for you. Gl guys and welcome