If you get concentrate, definitely dilute. I am lazy and get the ready-to-use spray. This is the one I use:
https://smile.amazon.com/Bonide-BND022-Pesticide-Organic-Gardening/dp/B0832WF4XW/ref=mp_s_a_1_13?dchild=1&keywords=neem+oil+spray+for+plants&qid=1611799538&sprefix=neem+oil+spray+for+plants&sr=8-13