I've been taking the daily bonus at ZulaCasino for several days, and I can say that 10,000 GC and 10 SC are enough to start playing without replenishing your balance. The GC run out quickly, but they give you the opportunity to test several slots and figure out what you like. You can read the bonus terms and conditions
here. For example, I tested Gallina Vinke from Jili, which is new to this casino, and this bonus was just enough for me to understand the game's mechanics. It's cool; you should try it. However, SCs are more useful because you can use them more carefully, and they are spent more slowly. If you log in daily, bonuses really accumulate, allowing you to play longer without making additional deposits.