I concur that it's crucial to read the rules and Conditions before making a first deposit and to make sure you are aware of any welcome offers' rules. This is true not just for getting to know about casino but also for making sure the section about the fairness of the terms and conditions is read. So that you can determine if they are actually doing anything or just influencing game outcomes in their favour.
Sincerely speaking, I once made a deposit at a brand-new casino, but I failed to read the terms and conditions of the promotional offer they offered, causing me to forfeit the bonus and preventing me from withdrawing until the deal was cancelled. Since I lost the deposited sum after cancelling it, I now prefer to read the terms of service to stay out of trouble.