You may start by

a) get a printed book, ebook or 'well structured' tutorial, says, systematically covering 10 to 20 topics instead of short tutorial on just one topic

b) this will get you covered for your task 1 to 3, but, only as individual tasks.

c) after mastering (b), try to combine them, instead of stand alone in tutorial

d) interrupt is advance topic and not be cover in many starting books. You can see http://arduino.cc/en/Reference/attachInterrupt

Since your post mentioned that you are relatively new to Arduino, in case you have not done below, you may start by

a) get a printed book, ebook or 'well structured' tutorial, says, systematically covering 10 to 20 topics instead of short tutorial on just one topic

b) this will get you covered for your task 1 to 3, but, only as individual tasks.

c) after mastering (b), try to combine them, instead of stand alone in tutorial

d) interrupt is advance topic and not be cover in many starting books. You can see http://arduino.cc/en/Reference/attachInterrupt Interrupt works only on certain pins, depending on which Arduino board model.