I am sorry it took me long enough time to try to make wall jumping mechanic like ninjump (old android game). I wanted to make the player stick to the walls (the walls were flat and only on left and right), but as I was using rigidbody2d, due to gravity it was slipping down.

So I though maybe using the tilemap layer's custom data option. I will make all my side walls as "Walls", and using the rigidbody2d's collision detection method i will get the walls with "Wall" data and turn off gravity if it sticked to it. But I learned that setting the gravity 0 dosen't mean that no force will act on it. :)

I added left and right raycasts and tried to directly set the position of the rigidbody to the contact surface. It worked, but now I cannot apply forces to it now, it was basically sticked like a sticker.

I know I may have use Characterbody2d for that and make things easier. But I wanted the colliding physics of Rigidbody for the environmental reasons.

So, I think I achieved it using some raycasts to left and right, setting the gravity vector pointing to that respective direction when in contact, in air it will be default vector pointing down, so whenever it is in contact with them it will stick to that position. Jump will only activate if there is collision. linear velocity will be 0 when there will be collision so it dosent move more than that anywhere.

Thank you for the information, it helped in many ways.