You do have the option to do a manual install instead of the opinionated install and there are a few resources
- GitHub - frappe/bench: CLI to manage Multi-tenant deployments for Frappe apps (Manual Install)
- This is a completely manual install which would give you an idea of what is involved
You don’t need to run it on a dedicated server, However, the resources required to run it and dependent on the the traffic, queries and data size you will eventually determines whether or not you need to run a dedicated server.
Note: Based on my experience in running ERPNext, I’ve found it ideal to install on dedicated Vhost and I use 2Gb ram as a minimum. The cost of Vhost are low now-a-days so its no longer a barrier, Yes its added management but in the long run its worth the investment.
Hope this helps