To avoid forks , don't keep two important pieces during middle game and opening in such a position that they can be forked especially when there is a knight in play, try to develop them safely (if possible ) .If the fork is only possible through your opponent's piece moving to a particular square , then you can either move one of your pieces or place a defender for that square . But mostly to avoid them , be aware of the position because pieces like queen may be on the far side of the board but can travel the board in a single move to fork your pieces if you are not careful
How to avoid a fork?

You need to visualize the board and do "what-if" moves in your head. I'm not saying a lot of moves... but a few... especially with the knight. Learn from your mistakes and hopefully you'll learn some of the common positions that are suseptible to forks.
Pretend to be your opponent and think about how you would fork your pieces.
On chess.com, you can learn to use arrows and hi light squares to help your visualization.
If you get forked... can you move one of the pieces to attack or capture a more valuable piece of your opponent (or check) to try and gain a tempo that would allow you to also move the other piece?

If a piece is two squares diagonally away from the Knight, it's nearly impossible to fork.
If you keep your King and Queen on opposite colors, a Knight cannot fork them.

Guys, to me this has been tricky and I need to know how to avoid a fork. So please help.
Based on your games, you shouldn't worry about forks and other advanced concepts. What is happening in your games is that your opponent attacks a piece, and you let him take it. If you want to get better, you should get rid of elementary blunders like this. Nothing else matters.
https://www.chess.com/game/live/98766260875

Guys, to me this has been tricky and I need to know how to avoid a fork. So please help.
Guys, to me this has been tricky and I need to know how to avoid a fork. So please help.