That depends on how important the website is. If it doesn't matter if the website goes offline for a few days, an unmanaged VPS is fine if you want to learn about server management. If you just need reliable hosting, get a management service.
buy managed vps with cPanel/WHM. ask your provider to secure the vps, set nameservers etc.. then when you face any problem just ask your provider or search in google. when i first bought vps it was unmanaged as the budget was low. I've done everything myself with the help of Google.
If you have no experience with server management, I will suggest to go for a managed VPS. cPanel licence itself cost $10-15/month.
Managed VPS will have everything installed and configured. But I will also suggest you to take a cheap VPS and do some learning.
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