This site gives some figures. Short recap: it was bad. It also depended on who you are – if you were Black, it was much worse than if you were white – or your location.
Lots of banks (9000, according to some sources) failed in the Crash, taking people’s savings with them. Also, mortgages were usually only for five years; homeowners had to refinance when the mortgage came due. Since there were no banks giving credit, lots of people lost their homes (even assuming they could make the payments, they couldn’t refinance with no bank available to do it).
Banks got into the trouble because they invested their money in the stock market; when it crashed, there was no money for depositors. This was made illegal until a few years ago and, since it was a major cause of the current mess, it may be made illegal again.
And the apple sellers on the streetcorners were no myth. You could buy a box of applies for a dollar and sell them for a nickel. You could make a profit if you sold the entire box.
But, like any financial panic, it all depended on who you were. My grandfather managed to keep his store afloat during the 30s, so they could tighten their belts and get by. It helped that the local bank remained solvent.