If you want a decent start, you should check out Liraspin Casino because their welcome package is actually quite generous.
They offer up to 450 euros plus 250 free spins which is a lot more than what most other platforms are giving away these days. I signed up a few weeks ago and managed to use the spins on some high-quality slots without any issues.
The site design is very clean and easy to navigate, so you won't get lost looking for the bonus terms or the cashier section. I personally prefer the mix of both deposit match and spins because it lets me try out new games for free while keeping my main balance for the big hits.
They have games from reliable partners, so you know the software is fair and not rigged. It is also great that they have a mobile version that works just as well as the desktop one. I have had a few nice wins on the Phoenix Inferno slot using the bonus funds.

Just make sure to read the rules so you know which games count towards the turnover.