The next village north of Carrick is Leitrim village, less than an hours cruising and an ideal stopping point while getting used to the boat. From here you head onto the Shannon-Erne waterway - there are 16 automated locks between Leitrim and Belturbet and it's not really an option for a short break. Leitrim is a quaint village with some good pub/restaurants and a service block although there's limited mooring. There's also an indoor shooting range with air guns and archery.
On the way to Leitrim you can turn off for Lough Key Forest Park, about three hours cruising from Carrick but be aware that there’s one lock on the way up to the lake that closes at 8:30pm in the summer. If you don’t get through the lock there’s a pub beside the marina near Knockvicar. Lough Key has a visitors centre and you could do the Boda Borg or Zip-It. Be aware that everything up here closes at 5:30pm-6pm but there are some nice walks if you decide to spend the night here. You could head up to the Boyle canal and walk into Boyle, about 20-25 minutes walk from the end of navigation.
If you want to try the automated locks on the Shannon-Erne Waterway there's a small village named Kilclare about 2-3 hours from Leitrim, which has a single pub and is a popular stopping point with hire boat crews as it's beside three consecutive locks - it's thirsty work taking your boat through. The last of these locks will be the eigth since Leitrim village.
Heading South there are mostly small villages on the way to Lough Ree.
the next town is Jamestown, about two hours cruising. Jamestown was once a fortified town and you can still see the remains of the fortification walls. There are two pubs here although one only opens sometimes, and a very good restaurant, the Cottage, about 10 minutes walk from the mooring.
Dromod is about an hour from Jamestown through one manned lock (all of the locks on the Shannon navigation are manned). Dromod always does well in the national tidy towns competition and has a picturesque harbour on Lough Bofin. There's a restaurant right at the harbour and two pub/restaurants in the village.
If you like a bit of isolation and cruising then visit Kilglass and Grange lakes on the way down. There a nice pub at the end of Grange Lake called the Silver Eel. Kilglass Lake is home to Shannon River Adventure, and adventure centre with kayaking, canoeing, archery and other land and water based activities. There's a pub close to the adventure centre called the Kon Tiki but food isn't served.
Less than an hour from Dromod is Roosky with four pubs, one of which does Chinese food. There's a good supermarket here and nice mooring along the river as far as Roosky lock.
Once you've gone through the lock in Roosky the next town along the way is Tarmonbarry, with two good restaurants and one pub just after the lock. When you pass through Tarmonbarry Lock you can turn off for Clondra, at the end of the Royal Canal navigation.
An hour from Tarmonbarry is Lanesborough/Ballyleague on the northern tip of Lough Ree. This town straddles the Shannon and the western side is Ballyleague in Roscommon and the eastern side is Lanesboro in Longford. There's a power station in Lanesborough and the hot water stretch just before Lough Ree is famous for fishing but note that stands are in great demand. This is the end of navigation for barges as they can't traverse the Lake.
This would be as far as you would expect to get on a short break before turning back to Carrick-on-Shannon. It's about 6 hours cruising to Tarmonbarry, and you'll need to allow for another 6 for the return journey.