Seeing different links: https vs www vs name.com link building

Hi folks, I have a question for you all that I am having difficulty answering.

I have an aged domain I am starting to work on as a money site with many old backlinks built over 8 years or so.

When I do tracking using LinkMiner product, I am getting 4 different results when I type the domain differently from links listed to Trust Flow:

https://www.sitename.com - 25 TF
www.sitename.com - 7 TF
https://sitename.com - 25 TF
sitename.com - 23 TF

Can anyone explain to me what's happening here, and if there are any updates that need to be made to site or domain to consolidate/make more powerful the link profile?

https:// should always be prefferred. Google ranks sits baed on their speed and security so HTTPS today is a must. That explains "http://sitename.com/".

Not sure about the sitename.com version - though it's probably going via the "https" link