Hi! So far from people who've beaten it they've shown that it could be done in 3-6 hours. This game is very friendly with items so please go to Tents with the Green Rabbit and buy Second Chances, as these are lives. In this game, you will find that you may die in 2-3 hits, as Printmaking Enemies are very strong and you are just Human, so having Friends and Second Chances is a must.
This game is also non-linear, so there's no natural progression of the game "getting harder" per se. You will not suck at the game! This game is very free form in its exploration so please feel free to walk around the print building as well, Rabbits and Shelves will give you money sometimes just for existing.
However, if you do want to start at an "easiest" place so that you slowly get stronger, I recommend starting at the Cyan Area located in the Second Floor Intaglio Studio of the building. Also please remember to use your Crafts. These are usually much better than just Attacking (Especially for Bad Girl).
I will probably make a small Tips and Tricks guide post later with images on when I am not as busy with other things. Thank you for asking this question.