DDoS is real for those who have experienced it. I’ve seen sites go down due to this. So, the best move is to use Cloudflare or something similar. Even their free plan can still do the job. It can help block nonsense traffic real quick.
To find out their customer service and tech support services, you can contact other customers and know about their satisfaction with quality of service. At the same time, technical support should be available 24×7 including holidays. Also ask for their average response and resolution time.