Questions on using Roon

I am seeing emails from Roon prospecting for new customers with a free trial period being offered.

Can Roon users please advise how one gets started with Roon?  I have a basic streaming setup running - in my case I am using a BlueSound Node 2i as streamer, with wifi connection, and then I use the Node's digital output to run into an outboard DAC which is a Schiit Gungnir Multi bit.  The sound is very nice.

I am now using the Blu OS app on a Samsung Galaxy Android Tablet to control the streaming.

I know the Node is considered a 'Roon endpoint', but I see some say that in addition to this, a separate computer is needed just to run the Roon program.  Is this true?  So a user that does not already use a computer be it a PC or Mac to stream needs to buy a computer just to run Roon?   That would be make cost of entry pretty high, despite Roon's low cost trial.

Also can the Roon system (computer, end point) run using wifi?  I live in an older house and do not have wired LAN in every room.