In many a contest, it happens to me that I am not able to solve a problem (even no problem), so I just need help with where to get the almost similar concept-based problem that I am not able to solve, so I will not make that mistake again (if any advice please help), I know that the problem set has many problems but I need the precise to the problem that I was not able to solve.
It is normal to not able to solve any problem at all. You need to keep trying and never give up. If you are unable to solve a problem, try looking up the solve and then try again.