Assuming you mean Newport, RI there's plenty of scenery although the road riding isn't great. I do remember speaking with a guy who has a 30 mile or so loop from Newport that he rides. If you have a car you can get to Tiverton (where I live) or South County which will open up more options pretty easily both about 15 min away.
There also are not a lot of bike shops in the area, search online for Newport RI bike rental and I think there's one that does do road bikes...or you could call any and ask what they have.
If you can get a bike I'd consider driving north to Tiverton and riding a loop down to Little Compton and Westport, MA. Generally nice roads and a lot of ocean view.
Newport is on the island of Middletown and islands, even sizable ones, can limit your riding options. 30+ Years ago I managed a bike shop on Thames Street called 10 Speed Spokes. We did a brisk bike rental business. Don't know if that shop is still there but I'm sure a good Google search would turn up a couple of rental shops.
As far as the riding, it's a tourist town, full of tourist traffic. A loop around Ocean Drive, about 10 stunningly gorgeous miles, combined with an ocean swim is a must do. For longer rides you can piece together a ride that snakes up through the middle of Middletown (pun intended) and see some horse farms and more rural scenery but some of the main roads are busy, narrow and filled with tourists who don't know what they're doing. The better ride might be to get over the Newport Bridge- I haven't biked over it in years so, check on it's bike access but cross over to the island of Jamestown and loop around over there. MUCH quieter.
Find your way ove to the East Bay Bike path up to East Providence for some nice scenery. There was a bike shop right off the path near the Dells (still open ??) You can ride over the bridge from Middleton (New Hope) but its kinda scary
I live practically on top of the East Bay Bike Path which is a pleasant ride and a short distance from Newport. My favorite place to ride, as Sakonett suggested, is the Tiverton/Little Compton/Westport, Mass. area where quiet, low traffic, rural riding is the norm. You can easily put together a ride of 30, 50 or 100 miles.
On rentals, Ten Speed Spokes is still in business and renting bikes on Elm St. adjacent to the Dinner Train. http://tenspeedspokes.com/ Send me a PM when you are about to head this way. I just did a ride they sponsored so it is likely they put on other rides. Try sending them an e-mail inquiring about rides.