Some back ground. I am a dad of an 8 year old that wants to play "An Orge and His Cake". I so bought the D&D essentials kit to learn how to run this for him. My brain is having a hard time understanding some concepts. I think I get it but need that pat on the back and a "thata Boy" :)

I know there are people asking better questions. I really apricate any help given to help me better understand this to helpfully bring some fun for my son :)

I will post the problem and example then post what I should do

This has to do with hiding and if someone can see them.

when you hide you make a Dexterity (stealth) check then add any modifiers
the enemy then has to Wisdom (perception) check then add any modifiers. I think that is the rule

So lets say a monster Goblin does a hide. They take a 20 sided dice role it. then add any stealth modifier.

The player then roles his/her 20 sided dice then adds any perception modifiers. If players number is higher then the goblin they seem it?

Example

Goblin roles d20 gets a 9 then adds 2 for stealth modifier has a total 11
Player roles d20 gets a 10 then adds 3 for perception modifier has a total of 13

since the player has a 13 and the goblin has a 11 the goblin was not able to hide from the player?