Recommendations for Self Hosted Servers for CTE program

Hello all, I am starting a CTE program on IT infrastructure and support. I want to purchase servers or server equipment that I can use as part of instruction. Some of the topics I thought kids could explore during their labs were Setting up Dedicated Servers on the LAN and running video game servers on them Setting up a self hosted LLM Setting up an application server for student projects Setting up a self hosted DNS Server Local File Storage for another CTE program Setting up a local Mail server ( no exchange, never again) We're on some grant money, so we can use this to purchase new equipment. I'm trying to figure out which of these servers can run on the same server (I'm guessing the video game and application server can run on different partitions), but I'm less clear about the LLM and the DNS server. I don't have a lot of experience setting up servers other than a Proxmox server I ran some software on. Can anyone give me some suggestions about how much RAM, CPU, and GPU power I'm going to need for those. Keep in mind this would serve about 20 students plus myself, so they don't need to be that powerful, but I'd like to purchase rack mounts so that students can understand what professional work looks like.