For newbies I suggest you go to Aliexpress dot com and buy bits there or Amazon. Buy the bits you need for the job at hand, and forget the kits. The nice thing about Aliexpress is you'll finds 3mm bits (1/8") in a variety of lengths.
I use 3mm single fluted bits all the time to cut 6061 aluminum, and had no problem with the quality of the bits, and have found some as long as 72mm in length, which I sometimes need when doing 3d wood projects.
You'll find that you'll mainly need upcut and downcut single and double fluted End Mills depending on the material, and V-bits (15, 60, & 90 degrees) for lettering, and (60 & 90 degrees) for inlays.
If you do any type of 3D models then you'll need some Ball nose bits