Skill points are acquired through hunting just like experience points; spending them in the skill menu lets you learn various skills.
Two bars fill together while hunting: level experience and SP experience. Each time the SP bar fills you gain skill points, and the on-screen counter shows your accumulated SP.
The classic tactic is SP farming: slowing your level progress early while stockpiling SP, so you don't reach cap with an SP debt.
The SP gauge: each fill of the yellow bar grants a skill point, with the accumulated SP shown beside it
