Just an option, but you may want to try using a LAVA HDTV DVR box (less than $50) in between your antenna input and your Roku TV input. Not only will you get DVR capability for your antenna channels, but you can use the box remote to control your channels and access your guide. It does take a little reading and practice for a novice to get used to, but may give you a big improvement in your user experience. By doing this, you watch your antenna channels through one of your TV inputs, just like how a dvd/Blu-ray player would integrate with your TV, as they also use their own remotes.
This is where I got mine:
https://antennadeals.com/DVRVideoRecorder.htmlhttps://antennadeals.com/DVRVideoRecorder.html
Unfortunately, it looks like they may be out of stock at the moment in most stores, but I bet eBay has some
There are probably some similar but better antenna DVR options out there on the market, just do a little googling or Amazon searching Be sure to read reviews to help understand what you are dealing with
