In the first level of the first pack, there are some signs telling you about how to play the game. There are also steps leading up to a cliff to jump off and get into the portal.
Read the signs, so you understand what to do. The signs tell you the rules. Then move right until you reach the steps. Then jump and press the right key at the same time until you reach the top. Then move right. You will drop down and in the process, you will gather the coins. Move further right until you reach the portal.
The only obstacles are avoiding falling off, and the steps (jumping and moving right at the same time may be difficult for beginners.)
"Left arrow key to go left"
"Right arrow key to go right"
"Up arrow key to jump"
"Grab these coins, they are good"
"The portal takes you to the next level"