How to fix this?? And what is the name of this problem??

How to fix this?? And what is the name of this problem??

That’s warp, the front edge of the boat is curling up a bit while printing and causing problems with the next layer. The fix would be active cooling for that part of the print or, if that’s not an option, turning down your printing temperature very slightly.

You need more cooling from this side.

The name you’re looking for that will probably help the most is overhang. As others have said, overhang is generally adjusted by tuning your extrusion & bed temperatures, as well as having additional cooling of the part. Also, reducing your layer thickness can help increase the angle of overhang you’ll be able to accomplish. Keep in mind though, this tuning will vary between different plastics, and sometimes even batches/colors of the same type of plastic.
Overhangs are any part of the model that are deposited without full support underneath, similar to bridging. What tends to happen is the plastic remains soft, and either curls up as it cools or as the printhead moves by. Ideally, for good overhangs, you want the lower layers to stiffen before layers above are deposited.

Wow such clear explanation @jesse_dean ​ thanks guys for your kind answer :")

reduce bed temperature after first layer.

Check cooling system ,increase the fan speed to max and adjust angle of the cooling wind.