As someone who absolutely loves Reaper, i'd recommend AGAINST it for you. I use Reaper (it's my secondary DAW after Ableton). I do music production, sound design, electronic music, and program audio software/hardware. It sounds like Reaper might not be what you want. You've really emphasized simplicity and ease of use.
Without any jest, look into Garage Band for PC. It'll probably be the easiest and cheapest DAW to record into. I've used A LOT of DAWs in my time. Some people joke about Garage Band not being a "pro grade" DAW, but it'll do everything you need it to do to record you and your friends/bandmates. And it focuses on being easy to use.
All the things that make Reaper amazing are probably the same things that will make you hate it. It's almost infinitely customizable, which means you have to spend a lot of time setting things up to work. And the workflow isn't 100% intuitive. There are a million great tutorials, but you'll have to watch a ton of them just to get up and running. And you'll have to sort through as many that aren't relevant to what you're looking for until you find what you need.
If you got the inexpensive Focusrite + Garage Band, a lot of it will be plug & play without hassle. You can worry about upgrading to a better interface or more full-featured DAW after you feel like you know what you're doing, know more complicated features you might want, and start running into situations where the gear and software limit you.