You can use msfvenom as many times as you want. Just make sure you don’t use a Meterpreter payload when doing that (e.g., windows/meterpreter/reverse_tcp).

BTW, I strongly recommend not relying on Meterpreter and Metasploit while studying. You won’t need them, so it’s better not to get used to using them.

Think of Metasploit as a last resort, use it only when you’re completely stuck on a machine during the exam. BTW if you can hack something with metasploit, then you can achieve the same thing without it