Cowski

I'm very new to this whole thing and learning every day. Today is Cura. I'm running v14.07 and would like to know how to set a number of initial layers to print at a slower rate than the rest of the print. Example, let's say I want to print the initial 8 layers to print at 20mm and the rest to print at 35mm (or whatever) how would I do that in Cura 14.07? Also, can someone explain to me what the difference is between Cura 2.5.0 and Cura 14.07? I don't understand why the same name branding but when the version numbers are so much different & the functionality is different. Thanks, everyone! Cowski