5e works differently.
Your Perception is your Wisdom Modifier plus your proficiency bonus - if you are proficient in that skill.
At character creation, you pick skills which you are proficient in, a selection based on your class. In addition you can pick a background which grants proficiency in two additional skills. A proficiency bonus is a special modifier which starts at +2 and scales with level up to +6. (Increases by 1 every fourth level after level 1.)
Rogues normally get Expertise at levels 1 and 6, which double the proficiency bonus they get in two of their skills (or one skill and Thieves Tools). That isn't in EA right now.
