2007 HONDA CBR 600RR OR 2001 SPORTSTER 883?

Which one of these would make a good first bike?

Oranges to apples comparison, but if a true beginner and don't want anything but one of those two, the Sportster.
The CBR 600 RR is NOT a starter bike, sorta like dynamite in the hands for a pyro.

Take a MSF Basic Riders Course before you do much else, than two aspirin and call again.

Neither. Looking at your older questions I would suggest a used late model Suzuki S40. Easy to ride, wicked quick on the city, capable of 85 mph on the freeway. You want a Cafe? Trivial to do

Depends on the person. Learning to ride a bike is an individual thing, i wouldnt want to learn on the street with anything, but if your mature and have a quiet place to practice anything can work. More or less though bikes can be quite heavy and have a high power level, both of which can become unmanageable very quickly in unskilled hands. Thats why they say its better to start off with a small light machine like a 250… Out of the two you mentioned the cruiser has a lower seat height therefore would be much more manageable to a new or small rider, still its a heavy machine. The choice is yours. Only you know you. My advice is get a dirtbike and hit up some trails for a few months, then get a street bike.