In a no deposit bonus, 10 free spins are probably the most common amount that you can get for free without depositing any money. Sometimes you can get 30 free spins, 50 free spins, 100 or more but this is very rare. But the more the better of course, depending on the terms of the bonus. If you make a deposit instead, you will most likely be able to get hundreds of free spins on a few gambling websites.
We recommend trying a casino first without depositing any money and if you like it you can spend some of your money.