How do i get minions
You buy skills via Skill Points. Press H > Skills and Traits > Slot Skills.
There you can find various minions to unlock.
You get skill points via map completion, leveling up etc.
Once you unlock a skill, you can load it on your skill bar when out of combat (click the tiny arrow above your skills and select the minion-summoning skill)
(edited by Sublimatio.6981)