Lets say i have Ace and 10. Most people would probably raise but i don't get why.
If You raise and get a shitty flop and your opponent bets you probably fold so that's one reason why i don't raise pre-flop.
A major mistake you are making: you are only thinking about your cards & what the flop does for you. Why fold just because you miss the flop & your opponent bets? Mathematically, it's likely he also missed on the flop. Chances of making a pair are like 37% or something - if he has something like Q9 & never hit, you are a big favourite here with A high.
Even if he hit a low pair like a 6, he would likely fold to aggression. This is how you should be thinking, not "what hand can i make".
one more reason why i don't usually raise is because the whole point of having a good hand is to win the most amount of money you can. so if you raise and everyone folds you only win small and big blind.
If everyone folds and you win the blinds then good... you win a pot & your table image improves as a player willing to get aggressive preflop. Then, you move on to the next hand.
In a cash game you need to consistantly raise preflop for 2 reasons;
1. You want to build the pot.
Say the blinds are $1/2 and you have a stack of $200. If you have A 10 hearts, no preflop raise, its just you and 2 other players to the flop and the flop comes 3 hearts giving you the nut flush. There is $6 in the pot. You want to get all of your money in. If you bet $200 into a pot of $6 everyone will fold. Infact betting more than the pot amount at all usually indicates a very strong hand. There's not much you can do here to build this pot without your opponent folding. Ideally here you would raise preflop to $6. Say 1 person calls, you now have around $13-$14 in the pot. So you could bet half, say $7. Your opponent may have hit something else like top pair or have a heart himself for a flush draw too, so if he calls, the pot is now $28. That's pot building, and it relies on there being money in it preflop.
2. You want information.
Some loose players will raise 3x with a wide range of hands, including 22, or 34suited. If that player gets a monster like AA or KK they will also raise 3x to disguise their hand. New players make the mistake of just calling to see what they 'can make'. But by only calling you have no idea if your opponent has 34 suited or AA. By reraising preflop you get a better idea of what you are up against. You can win a small pot vs your opponents rubbish if he folds, a flat call perhaps means something like 99 or 10-J, and if he reraises he probably has a big hand like KK or AA and you can fold. By raising preflop you can make more accurate decisions later in the hand.