The only thing that should concern new players who sign up at a new online casino is the credibility of the company. As long as everything is ok with its reputation and reliability, then there won’t be any problems along the way. If, on the other hand, the company (or its website/customer communication/terms & conditions) seems a bit questionable, its all-perfectly-looking on the outside bonuses with amazing terms are likely to bring you mostly disappointment.
They may either have unrealistic requirements (high wagers, low cash-out limits, for instance) or just be a dodgy website that will take your money, and you won’t ever hear from them. In any case, it will lead to your time and money – wasted, and frustration levels – raised.