Cloudflare CDN setup. How to setup?

Question

cloudflare

Hello, there was a DDoS attack on my website recently.
Timeweb installed BlackHole for my IP address and asked me to set up Anti DDoS.
I am an absolute teapot, and I did not understand much. Timeweb requested the following data:
1. a list of domains pointing to the server;
2. address issued by the security system;
3. addresses from which the protection system accesses the server;
1 - how did I understand this is my domain?
2 - I don't know.
3 are NS records in my domain?
Please do not judge strictly, I am a beginner 15 year old guy.

Answer 1

2) https://www.cloudflare.com/ips/