Wildflowers, harmless weeds, or invasives?

I have a hard time identifying plants without the flower ... hoping someone can help.

Photos 1 & 2:
I have a lot of this growing in one of my flower beds. I thought it might be asters so I have let them be. Now, I'm pretty sure it's not. Seems to want to creep/spread, like an agricultural clover. Anyone recognize this?

Photos 3 & 4:
Is this another volunteer veggie from my compost? Watermelon? Or weed?

Photos 5
Weed? Or fall wildflower?

Thank you in advance for your help!

 

The first is a Polygonum of some sort, looks weedable. I'm too tropical for the rest.

 

3/4 remind me of the first year growth of Arctium minus

 

Thank you!

I think I will yank them both. (I've got to get better at cooking the seeds in my compost!!)

Any thoughts as to the third one (final photo)?