Welcome @Tomuchan! The fastest you can complete level 1 and 2 is 3 days 10 hours each, after that it’s 6 days 20 hours per level.
Make sure to read the FAQ and the Guide, there is a lot of good info in these for new users. If you’re looking for further resources check out the community compiled list of resources. For extra features and fixes for those small things which keep bugging you consult The New And Improved List Of API and Third Party Apps.
I hope you’ll have a good time here with us and am looking forward to seeing you around!