Car won't move forward in 1st gear

Just bought a 2010 Citroen C3. But when I put it in first gear and press on the acceleration to move forward, it doesn't move and sounds like it is not in gear. I can put it into revere and it moves backwards but doesn't seem to move for first gear going forward. I'm pretty sure I have it in the correct position for first gear, but I'm not familiar with the car as it's the first time I tried to drive it. Is this a fault that can happen on this car - i.e you put it into first gear but it does not move forward (but it does move in reverse)? Any help would be appreciated very much. Thank you

I assume when you actually bought it, it went into gear?
Can you give us a bit more information? Did you buy it this way?

There might be a collapsed bearing on the gear shaft of the gearbox. Could be a broken selector fork in the gearbox.

There are two cables that push and pull on the gearbox selector actuator, on the gearbox. It could be that one of the ball joints has popped off or it could be that the cables are not adjusted correctly. The ball joints are located on top of the gearbox and on the bottom of the gear stick in the cabin. I would look there first.