Why do sharks have little fishes around them

Depends. Several species have been observed to do similar things.

Remoras attach via suction pads on the top of their heads, they get a free ride and pick up any scraps from the sharks feeding.
Pilot fish tend to swim around the shark's head. They are much more agile than the sharks so they can avoid being eaten (most of the time) and also pick off scraps.
Smaller fish, juvenile pelagic fish, fusiliers etc hang out just in front of sharks. They're generally too small and agile for the sharks to bother going after. They ride the bow wakes made by the much larger sharks reducing energy expenditure while they roam around finding new pockets of plankton to feed on.

Because they aren't big enough to be dinner for the shark(they aren't just mean eating machines, devouring everything in their paths you know). The ones that do eat the little fish ARE big enough to be the shark's main prey.

I bet this gives you enough to figure it out by yourself now.

It's like having a big friend to protect you. What predator wants to risk getting eaten by a shark for a tiny little fish? The fish are too small to be meals for the shark, but their predators aren't.

They have little fishes around them because those are the juvenile sharks and try hang around the woman sharks to be able to get food!

It swims so it doesn't get eaten by the shark and it cleans the shark too...

isn't that symbiosis ?