Which terms and conditions apply for specific bonuses are different for every casino. However, it is guaranteed that every bonus will have rules behind them. This could be the wagering requirements, the specific casino games available to use the free spins on, or any other requirements. It is extremely important as a new play to read the welcome bonus terms and conditions to avoid any surprises down the line.
There is a standard feature at any live casino where the initial deposit must be over a certain value. This usually sits within the range of $5-20 with different amounts depending on the casino, and sometimes depending on the specific offer at that casino. Usually, smaller deposits can be made but they won't trigger the bonus.
Regardless of how much is won via the welcome bonus, there is always a withdrawal limit that applies on any wins at a live casino. This varies heavily between different casinos but can range from anywhere between $500 to $10,000 in some cases. This means that winnings must be withdrawn in multiple transactions.