This solution is going to sound the same as all the others you see above, but with a very important distinction. Make sure you set your game difficulty to Beginner!!! I was playing on Semi-Pro and didn't realize that the default difficulty affected the Skill Games too. The moment I set my game to Beginner, I got Attacking Scenarios Skill Challenge on my first try after spending hours attempting to get it on Semi-Pro and only reaching 19750 or so. You basically just have to run towards the middle and shoot far or near side every time. And make sure you hold LT before you shoot as it gives you extra points.
I also changed Messi's stats to 99 for everything as well as Suarez and Rakitic (sometimes I had to score with them), made the Bohemians from the Irish league my rival team, created a 4'11" goaltender with 1 for all stats and put him as the starting goaltender for the Bohemians while also trading away all the other goaltenders from the team (but the game wouldn't put him as the goaltender in any of the skill challenges for some reason so I don't know if this step really does anything. I know because I gave him some killer dreads for hair, but the goaltender I faced didn't have that hair). But the most important tips are definitely setting the game difficulty to Beginner, making Messi 99, and shooting while holding LT!