If you have ENOUGH /ɪnʌf/ of something, you have what you need, you don't need more.

We are 5 people, I have 5 or 6 chairs = I have enough chairs, I don't need more
We are 5 people, I have 3 chairs = I don't have enough chairs, I need two more

If you have more than enough, especially if you have much more than enough, we prefer to use PLENTY OF

- Yes, I can go shopping with you, I've got plenty of time, I don't have to work today
- It was a wonderful party, there was plenty of food and drinks for everyone

ADJECTIVE + ENOUGH  

- Is it big enough for you?  (or do you need something bigger?)
- You're not old enough yet   (you need to be older)
- This house is big enough  (the size of the house is right)


ENOUGH + NOUN

- Have you got enough milk?  (or do you need more milk?)
- There isn't enough blue paint  (I need more blue paint)
- I have enough money to buy a car  (the amount of money is right)
 
ADJECTIVE + NOUN

When we have a group of "adjective + noun", we put it in one place or another depending on what we are talking about (the adjective alone or the noun+adjective group?)

1- I've got enough big boxes
2- I've got big enough boxes
 
Example 1 is talking about BIG BOXES, it is a noun, so we place ENOUGH before = Enough big boxes
Example 2 is talking about the size of the boxes, "big", so it is an adjective, we place it behind = Enough boxes

- I've got enough big boxes  I need 4 big boxes and I have 4 big boxes, everything's ok
- I've got big enough boxes  The size of the boxes is right, they are not too small, they're ok

ENOUGH alone

We can use it alone if it is clear what we are talking about

- Would you like some more chips? - No, thanks. This is enough.
- How many chairs have you got? - Enough.
- When you have a lot of money, you never have enough.