How do I figure out my opponent's weaknesses? Are there any shots I should play to figure out and exploit their weakness?
Your question sound a bit...too broad and vague. Are you new to the game? For starters, hit to front and back corners. Or if you have the chance to watch your opponent play before hand, even better.
You could test possible responses to: - punch clears to the backhand rear court - deceptive slow drops - fast drops - backhand/forehand defense - low/flick serve - long high forehand serve - ...
Just keep in mind that fitness could be a big weakness as well. Best way to figure out their weakness is to watch them play a few games or just experiment and see what works for you.
Easier said than done in a short period of time (e.g.: in a tournament against someone you never played before) as your opponent will try to cover up their weaknesses. Rather, you should figure out what their STRENGTHS are, and try to avoid giving them those shots to hit. If he has a really good smash, try to limit your lifts, etc
nice quote from the film "Rounders" (according to poker, but it obv works here, too...): "If you can't spot the sucker within the first half hour at the table, then you are the sucker."
This is from my experience 1. Look at their physic. in general, tall players have better reach, but less agile. Small players are agile, but have less reach. Thin players have better technique, but lack power. Big muscled players have big power, but less technical. 2. Test 4 areas with different height and check his response high and low hits to the front and rear of his left and right. but in general, the backhand area is the weak point in every opponent.