Honestly, if it’s just a small, personal project, just use common sense and take some basic precautions (e.g. use a firewall, use NGINX instead of serving Wordpress directly, etc.).
Note that CloudFlare doesn’t protect you from everything either - it only provides some very specific services. A rudimentary level of caching images being the most common one a free account level would be able to use.
Modern CPUs can do all the audio processing you’d ever need (maybe barring some professional use cases like making music or editing a movie).
Audiophile external audio devices are just doing the conversion from a digital signal to an analogue signal.