Actually .... if he has a freewheel, not a freehub, there might be spacing issues if he tried to move up to more gears and a freehub. Also, he would need to buy not just a rear wheel, but a new rear shifter. Even using Microshift or whatever, now we are talking a few hundred dollars in parts for a bike which probably cost a few hundred dollars. ($3889 is about the average I have seen online.)
CCM Presto 700C Road Bike
https://www.canadiantire.ca/en/pdp/c...?rrec=true#spc
22.5" aluminum frame---700C tires---21-speed Shimano Revo grip shifters---Shimano derailleurs---Alloy calliper brakes---Alloy rims and stem
Ride it and enjoy it but do not spend a penny on it besides maintenance. This bike cannot really be upgraded. I mean, you can buy a wrecked Ford Pinto from a junkyard and buy a big motor and new suspension and a new interior, wheels and tires, new electronics ..... and you would be left with expensive trash. Just like a $600 car, you put gas in it and drive it to work and save for a new one.
Nothing inherently Wrong with the bike, but all its components are the cheapest and weakest---except for the ones which are the cheapest and heaviest. The freewheel is an outmoded design, but replacing it wouldn't be worth the cost. Save the money and shop around for a better bike.
The deal is, a $300 bike can work okay if you don't use it hard or depend on it much. A $600-$800 bike can do everything a lot better for the rest of your life. There was a guy on this site a few years back who put thousdands of miles on a Decent entry-level bike--A Dawes Lightning from Bikes Direct, $500 at the time. I rode thousands of miles on a similar bike.
When I started cycling as an adult I was broke, so I collected junk bikes and fixed them and rode them. I cannot tell you how many times I have been let down by cheap parts, or how many bikes/wheels/bottom brackets/cranksets/et cetera I went through before i finally saved up enough for a real bike. Once I got a real bike, I was shocked to find that real bike parts keep working for years, not weeks
I have ridden thousands of miles on junk bikes, and mostly enjoyed them. You can do the same. But if you plan to ride with vigor and enthusiasm, treat yourself to a decent bike.