That question is rather tricky to answer.
I’d generally recommend sticking with the Algos for now, and getting a Vexor when you feel like the PvE you do can’t be done in a feasible time with your Algos anymore.
You want to have some solid support skills (skills at 3 or higher), especially for the medium drones before upgrading to a Vexor really makes a difference.
If you mean the “mastery” skills in the ship-info, then I’d say going till 3 before you get a Vexor is not a bad idea. Although the skills recommended there should be taken with a grain of salt. If you use a shield-tank for example, skills for armor-tanking won’t help you at that moment.
So read what every skill does and when in doubt, don’t hesitate to ask questions. 
You also might find this guide here useful: