First, register your domain with Podpage at https://www.podpage.com/setup-domain.
Then, to get your Podpage to show up when someone goes to your domain, you'll need to log into your domain registrar (the company you bought your domain from) and update your DNS Settings.
If you don't know where to find these, just Google "How to change DNS with _______" adding your registrar's name.
Once you get into the DNS settings area, do the following:
1) Disable domain forwarding
If you've previously set up your domain to forward to another domain, remove that. This can cause errors with the other DNS settings
2) Add DNS Settings for Podpage
Follow the instructions below to set up the DNS for your website. Note: if you're asked for TTL, just leave it blank or default.
To set up your whole domain for Podpage (www.yourdomain.com)
Go to the DNS records section and add the following records:
CNAME with host/name www that points to / value of domains.podpage.com
A Record with host/name @ that points to / value of 54.90.47.105
If you see any errors, it might be because you have conflicting DNS records already (you've already set www, or there's already an "@" A Record. Just delete them.
To set up a subdomain (podcast.yourdomain.com)
In the same place, just add the CNAME (not the A Record)
CNAME with host/name yoursubdomain that points to / value domains.podpage.com
3) Save and wait
Give it a few hours to totally switch over. In that time you'll see the page not come up, potentially some SSL errors, and more. This is just the internet doing its thing.
You can find more details setup at https://www.podpage.com/setup-domain