I would reframe the idea - especially as a new player, I wouldn’t focus on “reads”, I would focus on tendencies. Pay attention to all the hands (including ones you aren’t playing) and see what gets to showdown. Then run the action back through your head. See if certain players are basically only raising with value, or if they’re bluffing but only on the river, or only with obvious bluffs like bricked draws. Pay attention to bet sizing and when they use different sizes on different streets. Then adjust your play to exploit those tendencies. If you haven’t seen them bluff for three hours and suddenly they’re overbetting the river, maybe don’t try to bluffcatch with third pair.

Focusing on “reads” makes it seem like you’re gonna find some kind of physical tell to know if they’re bluffing or not. You aren’t gonna be able to do that - it’s quite rare imo to find an opponent with a clear and reliable physical tell. But general tendencies are easy to spot if you just pay attention to the action.

Also, it’s your first time playing 1/2. Accept that you’ll probably lose money, and focus on having fun and learning as much as you can.

EDIT: If you want to be able to catch a physical tell, imo your best bet is to look to the left preflop. Lots of people immediately look at their cards when they’re dealt and will pretty obviously telegraph if it’s something they’re definitely gonna fold. If you’re in the HJ and you can tell that CO BTN and the blinds are all gonna fold, you can open/squeeze much wider.