DNS, VPN, and dynamic routing

In the company I'm working for, we have a training project that involves 30 teams of 4 people. Each team must be able to reach a VM by resolving a domain (let say training.domain.com).

As we have 30 replica of the same VM, my idea was to run each one of them in a separate subnet (10.0.1.1/24, 10.0.2.1/24 ... 10.0.30.1/24) and somehow run an openvpn server that would restrict for each team the access to it's own VM / subnet.

My idea was :

1. Team member run VPN client
2. Team member resolve DNS training.domain.con that returns some IP (VPN server IP ?)
3. This IP is translated to the proper private IP according to VPN connection (ex for team 7 : 10.0.7.1)

But I'm really not used to VPN config, and I'm not 100% sure how to setup this environment.

Am I going in the right direction ? Is all of this feasible ? Should I run 1 global VPN server or 1 per private subnet ? Maybe VPN is not the solution ?

Thanks alot for you help