I just picked up a TC Electronic Ditto and it's been a joy so far. It's extremely sparse/minimal for a looper, with one knob for level and one switch. Record/Overdub/Stop/Erase are all controlled with different combinations of tapping and holding. It's missing a lot of features common on more complex loopers but I dig it for my purposes.
Boss's RC series is pretty much the industry standard as far as loopers go, so you can't go wrong there. Digitech's JamMan series is also comparable. I used to have the JamMan 2-Pedal model (I think it's been phased out since). If you're looking for the ability to store loops and create a log of them, import them onto your computer, match/set the tempo, and other non-playing features like that, you're going to want more of these style.
Final recc is to check eBay. Loopers tend to be useful tools for specific applications but not as handy as most think. This means there's pretty high turnover so you the used market is rich.
While I'm at it, I've been using
www.learnjazzstandards.com as a resource for playing along to basic standard tracks for a few years now. They've also got a youtube channel, which is how I discovered them.