I don’t know how many floors in this building but I am sure that each floor would be a challenge for you. You can up-frequency by elevator or stairs but I think your stairs is a top choice. In this map you can see experience a fully working automated elevator. You can use it as a blueprint for your own elevator to better understand how redstone can be used.
To use the elevator step into the circle which can be seen in the image below. Then turn around and switch on the button. Instantly after you will be sent up to the top floor.
Overcome all the challenges and win