Personal opinion, but I would not use Portainer for everything. Browsing, playing with containers, okay, but most of the descriptions will be for plain Docker commands or Docker Compose. Not to mention how important it could be to reproduce what you already done before without relying on a webinterface and the availability of Portainer. About handling volumes and folders in Portainer, you could try to ask in the Portainer community, but as far as I remember, you can create volumes from Portainer and also bind mount folders using absolute path.