Your main issue with the code above is that you are using "int" where you should be using a variable. All you will have to do to get it to compile should be to convert the places you were trying to use an int to use a variable.
for(int i = 1; i <= user_Input; i++)
{
final_Value = i * user_Input;
}
Changing to the above should compile, but now you will need to get the proper logic inside the loop. Since final_Value can only hold one integer value, every time you go through the loop, you are overwriting it instead of multiplying to the previous one.
Hopefully, that second part was enough of a hint that you will be able to figure out how to find the answer.