I still have opened pots of acrylic paints from several years ago that are still good. As long as they are sealed properly.
Just check if they are not completely hardened. Sometimes it's just the top layer that has dried out. Other times the paint has just settled a little or has thickened. In that case just stir them up and/or add a little thinner/water to thin them down to the desired thickness.
If they are dried up and hard, then throw them out and get a new ones
I hope that helps and good luck on your projects,
Rick