Welcome to CoffeeSnobs!
Firstly I would suggest reading less and roasting more... serious... you learn so much from doing it and your roaster, setup and environment is unique to you. Anyway...
I would suggest trying 250g roasts (that will give you 8 to learn on from the 2kg)
Start with the Preu or the Colombian.
Rule of thumb, aim for 10 minutes to 1st crack and another 3-5 to second crack. That is only a guide, 8 minutes to 1st or 15 minutes to first might be ok too. (take lots of notes)
1st shot should be when they are cool enough to go in your grinder. (taste and make notes)
Leave the rest in a valve bag and try it again in 2 days (taste and make notes)
Try it again in a couple of days (taste and make notes)
Repeat until you have no coffee!
take lots of notes!
Don't look for a "paint by numbers", coffee roasting isnt like that, instead learn as you go and in no time you will have a technique that suits your setup and your taste buds!
Remember, you are talking about a couple of dollars of beans each time, not a kings ransom and you will learn more by under roasting and over roasting a batch and tasting the result.
Most of all, enjoy the journey!