Each gamemode gives you a different amount of tokens per question. In general, the Gold Quest or Factory gamemodes are best for getting lots of tokens due to their fast pace nature. You can find a chart of each gamemode's tokens per question HERE. In these 2 mentioned gamemodes, you need to answer 400 questions correctly to get the max tokens per game. The time it takes can vary from 15-30 minutes depending on your answering speed. The most tokens you can get in one day is 500 plus your daily spin.
How do I get more Blooks?
If you want more Blooks just simply open more packs, or wait until seasonal packs release, participate in events (like CoC), and buy one day chromas on Valentines Day, St. Patricks day, and Easter
The strategy needed to win depends on each gamemode. A list with each strategy to win can be found HERE. Please keep in mind these strategies will not guarentee you a win, they are just strategies that may help you get a higher score.