Older dual core E7200 maybe, 2gb system ram, 250W power supply= very, very limited gaming. No matter what videocard you might buy, you'd need to stick to 2d games or older(like Half Life 2) 3d games.
The CPU support list for that motherboard doesn't list any Core 2 Quads as acceptable. So you're stuck with dual core. An older card, like an HD 7750, would be best. I recommend that one because it doesn't require much power. For more powerful cards, or for older used cards which can run games, you'll need to upgrade your power supply. The older gaming cards tend to use a lot more power than newer ones.
Just remember, play only dual core friendly games. No PUBG or GTA V on this system.