I just speedran the first couple of days. Mary calls you as you walk out the front doors of the school (not using the map to leave the school) the day you get the huge list of tasks after the accident.
Also prior to getting the call: I did take max for a walk (opened the park), I assembled the binoculars, I clicked on the broken fence and the boards over the hole looking into Sara's yard, I talked to Mary in the living room about grades, I talked to Mary on the sidewalk (opened the mall), and was attempting all the morning tasks listed (I only had spy on darnell and another dull class awaits on the morning task list when I walked out - I wasn't working on the day/evening or general tasks list).
If you are playing v0.82.4a or b - even if you didn't have the bug, I would recommend downloading v0.85.1a and starting over. However, the bug still rears its ugly head in v0.85.1a for some.
I would just go back to a save prior to buying the items, first, and going from there. If you think that is too far back, then sure.
There are 81 save slots in the game - I would also recommend saving every 3rd morning. (Save slot 1-1: Day 1 (after all that prologue stuff), Save slot 1-2: Day 3, Save slot 1-3: Day 6, and so forth). That way if you run into something you can always step back through saves.