There's not really a single definitive route due to how many medals there are that are easy to miss and going back for them would waste more time. It also depends on which skips you do, so if for example you don't do the big Rooftop Run Night skip there's a couple more you could get there. I'd recommend you collect all the in-stage medals at least once so you have some knowledge of where they are, then look at the WR and memorize which medals that gets. Then look through the stages and find some more medals that don't take a lot of time to get and add those to your route. My first route I went for I think 125/85 medals, so by the end of the run I'd usually have a few too many so I could skip some then. It's not optimal but the time difference isn't huge if you pick the right medals. Hope this helps you a bit and it's good to see someone interested in running the game again!