Is this a Weed?

I have been told this is a weed. I am new to gardening and am starting work on a very poorly maintained garden left by previous owners...

My garden is overgrown with these 'flowers' but are they weeds?

 

Hello and welcome to the forum Erinthae
I don't know what that plant / weed is, but it's nothing special.
I would just treat it as a weed in among the other jungle there - nothing special to be rescued.
I hope you get on great with your garden.

 

Green Alkanet, so it depends on what you intend to do with your plot! It could stay if you are going for a wilder, natural look?

 

Is it not comfrey?

EDIT> It's Green Alkanet. Flowers on comfrey are different