It is not a problem to have the invercone up and take a reflected reading.
Incident readings are quick and effective, but should not be the only metering method on your repertoire — for now, just startingn out, yes, but in the future, diversifying into spot metering will kit you up to tackle even the most difficult lighting with relative ease where incident or reflective will not work.
For beginners, the time-honoured approach of measuring the light falling onto the subject by way of aiming it back at the camera, holds well. An extension of this (on meters equipped with memory function, which is very useful) is to use the memory mode: read one side, place it in memory; read the next, place that in memory too, and another, then average. An example is portraiture with mixed ambient lighting where the face is unevenly illuminated — all aspects of light are measured.
There is no substitute for actively experimenting with metering when you first start out, and taking notes as you go along, which you can reference later when you are viewing the negs. Be sure to set the meter to 1 or half stops (for negs) or 0.3 (third) stops with transparencies. Readings for negs will allow you some leeway for making mistakes, while metering for transparencies will require you to be more discriminating and accurate.
With whatever film you are using, what faults you see will effectively be a springboard to launch you into getting progressively better results by repeating your work and making variations.
As you can see, there is some debate here on just what method works best, and that debate will no doubt grow and grow and grow.
Have a look at Sekonic's own How to video here.