I have not been but I have friends who go, they say Managua is dangerous, not a good idea to go by yourself, but plenty of tang there. If you have someone who knows the city, then it's good and plenty of poonage.
Most prefer Granada, pretty safe, beautiful historic town, some hotel, may be listed here, caters to mongers but not a lot of girls.
Beach towns on the Pacific immediately due north of Guanacaste are supposed to be fun and reasonably safe and cleaner than Jaco, but my toilet with fresh laid 2 lb steaming diarrhea turd is cleaner than Jaco...,
Some Americans own bars and restaurants there and hotels are cheap, it is hot like Florida or even worse but they say lots of fun, not sure about girls but these are impoverished third world sssshhhttt holes and I bet girls gravitate to where billionaire Rich Americans are,
and Nicas are amazing.....