Let's see. Kinda lame, but I will go get me some hardware. I want to get into self hosting and woth that much money, I'm going to order a high-end Synology NAS, but first I'll buy a house for my parents to live in (so I will have that hpuse as the postage address, duh), and set aside enough money to cover all of my living expenses at University plus some extra. Look through my options for starting a business or investing them, and if a business seems like too much work, I'll get a relatively small investment portfolio of about 50 Million, to cover all of my living expenses for life, which at a stable 3% annual dividend would get me about 1.5 Million p/a or just over 100k monthly. Of the rest, I'm leaving 225 Million for myself to try creating some businesses, invest in companies, organisations and projects that require it (1 million to the GNOME Foundation, 1 Million to KDE, 1 Million to XFCE, 5 Million to the team behind Cinnamon and Linux Mint, 1 Million to the Elementary OS team, 1 Million to the Nix and NixOS Project(s), 5 Million to Debian and 5 Million to Arch).
That leaves me with 205 Million of which I would like to use 5 Million to try out some businesses, see if anything works out, 100 Million to invest in making the Best Linux distribution for New users under a Company, with these resources giving me the ability to make something truly great, and to market it, to rival Microsoft, and to get Linix on the desktop to where it really needs to be, both for home users and enterprise users. That leaves me with 100 Million which, after all of these projects, I should hopefully be aware how to use to become a Venture Capitalist, but not for some profit-driven companies, but rather companies which respect a user's privacy and right to repair. Now, If you did the Math, you might have realised I still have about 225 million left. Of these 25 Million to my parents, to do with them as they wish (likely invest them and retire immediately) and 200 million for various environmental causes, because we really are killing the planet.

To actually answer the question:

Actual Purchases:

Synology NAS

Other Hardware, such as:

An M2 Mac Mini for its power efficiency,

A Framework Laptop for its modularity,

A High End System76 Laptop, to support an awesome company

A bunch of Raspberry Pies (the SBC not the food)

Some actual servers

Non-Hardware:

A house

An investment portfolio

Maybe a company

A lot of donations