I've read that Bach inventions would be a good place to start?
No...don't go there...not a place to start...There's so much you could use...there are many sites on the internet where you can download piano syllabuses (couple of examples below), and they have lists of pieces in different grades (= general difficulty level). In Youtube there are playlists with graded piano repertoire.Or you could get a sheet music book that has a selection of music for a certain grade. Try the earlier grades (2-3) and if they feel much too easy just go up. There are some nice pieces among the very easy ones too.And of course this site (Pianostreet) has lots of piano music to download and it's searchable by difficulty. You need the gold membership to download the sheets, but you can search pieces without it and then look for the sheet somewhere else, like IMSLP.If you're into books, I highly recommend this one, it will help you find pieces that are not too difficult but still interesting and also you can learn about new composers:https://www.amazon.com/Pianists-Standard-Teaching-Performance-Literature/dp/0882846558/ref=sr_1_1?s=books&ie=UTF8&qid=1375723012&sr=1-1&keywords=jane+magrathLinks with repertoire in different grades:https://www.abrsm.org/regions/fileadmin/user_upload/syllabuses/pianoComplete11.pdfhttps://www.musicdevelopmentprogram.org/sites/default/files/files/MDP_PianoSyllabus_2013%20online_SECURE(1).pdf