Is 2 acres enough to create a paintball field?

YES! my piece of land is about an acre and there is a house on it.

Generally speaking yes, but a piece of land may not be big enough even if its 10 acres or it may be big enough if only 15 feet by 35 feet! It all depends on the ZONING of the land. SFR, or Single Family Residence zones can be high density or low density. The higher the density, the more units can be stuffed onto a certain square footage.

Ive seen 40 acre parcels that cant be built on because the zone required 120 acres.