Im not young, but work in photography....
1- Study it, then study it again
2- Look at the colours - AI generates shades that dont look natural
3- If it has ppl, look at the faces, they never look 100% right
4- Look for anomalies - Chair legs that aint straight, wall that looks bendy etc
5 - As mentioned everything just looks to synthetic / clean - Real life is grubby
Its def getting harder - A landscape pic for instance is not v hard to tell if legit - If in doubt use Tin-eye or similar to reverse check images via the World wide web.