how to develop a partial roll?

I have an excess of expired color film i got for free, and I want to develop it in b&w chemistry, but I dont know what the developing times should be. I am planning on cutting one roll into multiple strips, and developing each strip for different amounts of time to test how I should develop the other rolls. How should i go about developing a small strip?

-Do i still load it onto a film reel?

-If its smaller than is reasonable to load onto a reel can I put it loose inside the developing tank?

-should I fill the tank fulky with chemistry or is it okay to not have a full tank?