Reddit mentions of Continental Country Plus Reflex Bike Tire, Black, 26-Inch x 1.9

You can run pretty much any 26" tire that is in the ballpark of 2" wide, say 1.75-2.25" to be safe. That said, I wouldn't recommend that cruiser tire at all, it's got a very square profile that will negatively impact the handling of the bike (it won't corner worth a shit), get poor traction, and they are just junk tires in general. They are meant to go in a straight line on pavement very slowly, and that's about it.

A fairly street oriented tire will still handle wet grass and light snow, you don't need to get a knobby mountain bike tire that will slow you down on pavement. In your price range the [Continental Country Plus](https://www.amazon.com/Continental-Country-Plus-City-Tire/dp/B00B35ZNXU/ref=pd_sbs_468_7?_encoding=UTF8&pd_rd_i=B00BBY8R0O&pd_rd_r=KG5TESQV53WJ96AQ8FHV&pd_rd_w=Kkh2E&pd_rd_wg=FSTzG&refRID=KG5TESQV53WJ96AQ8FHV&th=1&psc=1 will be a much better option. They will perform better in every way. It's got enough tread to handle the conditions you expect (I run a similar tire in similar conditions, it'll work) while still rolling well on the road.

You don't need to convert anything to tubeless, nor is there a good reason for you to. These tires use regular tubes. If the ones you have are as old as everything else, I highly recommend replacing them when you replace the tires. They are sold by diameter as well as a width range that it'll work with. For example: 26" x 1.75-2.5". Just make sure the width you need is between the range listed. They are also sold with different valve stem types, Schrader (like the kind on a car tire) or Presta. I'm almost certain you'll need Schrader, but it's worth double checking. Get a spare to carry with you (along with the means to change and inflate it) for the inevitable flat tire out on the road.

While you've got the tires off, it would be prudent to clean up the rim and replace the rim strip which is likely to have deteriorated by now. You can buy a replacement, but I always just wrap the inside of the rim with a couple wraps of electrical or duct tape and poke a hole for the valve stem. You just need something there to protect the tube from rubbing against the spoke nipples and causing a puncture.

To get the most life out of the new tires and prevent flats, be sure to frequently top off the air pressure to the maximum pressure listed on the side of the tire. It will reduce wear and prevent pinch flats, which are cause by low pressure.