What is best to use

Hello from a newbie here
Sorry if this has already been asked but I’m not sure how to search for this topic
Am I better using Legendary items even when I have a much higher item in my collection
For instance I am using the legendary broken crown which has 213 armour and a marquise ruby installed but I have the rare champion onslaught in my inventory
Same question goes for other armour and weapons

I am a lvl 65 barbarian and am using the nephalem rifts to increase my levels

Thanks for any replies

Short version…
Your priority is getting to level 70. Any helm with a socket in it can be used, preferably with the largest Ruby you have available socketed into it, as this gives you increased XP gain.

Longer version…

Thanks Meteorblade
The reply is appreciated
Il have a read through the hints you have posted for me
Im a returning player after quite a gap and am generally just bashing through the levels to get me to level 70 and have to say that there is a lot of things i dont quite understand but hopefully the tips in the links will help
I have to admit that I’m a button basher (playing on the Switch) and usually end up picking most dropped items lol