How best to transfer items from old to new mac?

i don't want to transfer 'bad stuff' from my old macbook pro to my new macbook air.

I understand how to transfer my whole system, but that would also take old stuff that i want to leave behind. You are talking to a dummy here, so this is why I would love my new mac to not be infiltrated by bad stuff. I have done housekeeping as best I can on my old mac.

I believe I can pick and choose what to take over using a different method. I have only just found out where my emails are. Using this as an example, do you think it a bad idea for me to decide what to transfer? I'd hate to lose items. I really only need to transfer all my word documents and some software I use, eg, my family tree software from Ancestry. Apart from Word, my tree software (that was downloaded using a disc), emails, I can leave all else behind. Please give me your thoughts.