You will need the following to get dynamic DNS working on Cloudflare:
Cloudflare as your DNS provider. Migrating from your current DNS provider over to Cloudflare is easy and free whether you are using Godaddy, Namecheap or another one.
A reverse proxy such as Nginx will come in handy if you need to host multiple apps on a single domain. Here's a 5-minute how-to.
If you are looking for guidance on integrating an open-source commenting system such as Remark42 to your site, here is how I did it.