Hoping you are sincere about this because it will involve a serious amount of your time and it will be a truly frustrating experience to back out midway realizing that what you invested on did not lead you to what you are trying to accomplish in the first place.
The first thing is what is your end goal? Hosting using Debian for what? Hosting can mean a lot of things. Are you trying to host a game server? FTP server? Hosting a streaming platform? Web server? Self-hosted? Cloud hosted?
What does Xfce stuff means? Are you planning to be Desktop Environment developer? Or are you referring to the console typing commands/running scripts? Or are you developing a desktop app for Linux?
Debian is an Operating System similar to Ubuntu, Windows, MacOs, etc. It offers you tools and an environment to work on something. However, in order to develop something you will need more than just an OS. You must know several programming languages, probably a bit of systems administration, networking, database administration if your application requires it, and nowadays a framework. Think of Debian as a Swiss-army knife. It has lots of built-in tools free. It can open a bottle of milk, cut through a bag of flour. It can unscrew even the service panel behind your oven. But if you want to bake cookies, a knife is not enough.
Note also that before developing something, for the most part, people underwent a certain level of education, additional training, a route of specialization, and maybe certification. This is a profession for some people after all. However, if you are just starting, a hobbyist, an enthusiast, or from a completely different field, do not be afraid! It is still possible. You just need to put the time, effort, and patience. There will be lots and lots of reading (RFC, white papers, documentation, manuals, bug tracking reports, logs, other peoples’ code, etc) and self-investigation.
If you are unsure where to start, start from the source of what you have. Most of the time, an official guide is already supplied and will be sufficient. Search also for FAQs. Then look for the specific community forum/wiki or mailing list. Probably the exact problems you are experiencing were experienced by some people before and were solved already. If everything fails, Google is your friend. Good luck!