neck sizing if you don't have ejection problems.. full length otherwise

Whats nice about neck sizing is you have brass that fits your chamber perfectly,greater accuracy and longer case life.I also use the Lee factory crimp on all my reloads.The beauty of this die is it works with any bullet and also helps accuracy.

I trim every time.

I trim every time and clean every time. I have picked out a lot of defective brass by checking it when trimming. Some factory defects (I size and trim new brass) some defects from firing. Being new to reloading, you should stay away from neck sizing. I have been doing gun work for almost 40 years and reloading has caused more problems than it ever solved. Read your manuals and go slow until you get a basic understanding of reloading. Be leery of reloading "Advice".