How to model this seat with curved edges/corners I would like model this seat. I'm using version 2.91 at the moment.

I have not found a way to smoothen the blunt edges. Currently this is the state of the seat:

Note that the edges are rounded in the initial image. How would one do this using the least complex method? I am fairly new to Blender, and am not yet familiar with 98% of the functions. I would also like to be able to make the corners rounded. Does anyone have any advice?
Thanks
Yes, itś really simple, all you have to do is shade it smooth, in other words, find ¨shade smooth¨ and click that. DO NOT just add more faces until it looks smooth, blender will likely crash as it did with me.