No worries. Definitely try and get a younger player to train. SFs are hard to train and take a lot of time, but are very valuable. I would recommend trying to train Bigs or Guards first as they are easier to train, but if you are set on training up an SF, aim for an 18 year old with respectable outside defence, respectable inside defence, at least mediocre driving, at least mediocre passing, at least mediocre jump shot and at least mediocre inside shot. At least that's what I'd be looking for, if one of the stats is slightly lower it may still be worth getting it as the player is still so young.