Congrats! I never thought that applying by foot in companies are still a thing. I've never done it, to be honest and I don't know that tiring feeling, it seems so stressful, and that you have to walk under the heat of the sun. It's a great experience though, that you can learn.
If you didn't land on that OJT job, I would suggest you check out online job websites and LinkedIn. Many are posting jobs there - including OJTs. These days, it's kinda the thing.
I got my recommendation for OJT from the school as well, does your school have that?