里 is 田 (field) over 土 (earth) — the land where people settled, a village or neighborhood. From 'the place within' it came to mean 'inside'. It's also an old unit of distance (about half a kilometer) and the inner lining of clothes.
里 (often written 裡/裏 traditionally for 'inside') is how you say something is IN a place: 这里 (here, 'this-inside'), 那里 (there), 家里 (at home), 哪里? (where?). It comes AFTER the noun, unlike English: 书在家里 = 'the book is at home' (book-at-home-inside). With 这/那 (which you know), you can now point out here and there.
A field (田) on the earth (土) — the settled place WITHIN. INSIDE.
里 goes after the place, not before: 家里 (in the home), 这里 (here), 哪里? (where?). Chinese puts the 'inside' on the back end.