Looks like Chenopodium album, lamb's quarters.

Here is a link that might be useful: Info here

Here are the small vegetable or fruit growing

Oh then nevermind what I said.

There are similarities to Physalis pubescens, aka Eastern Black Nightshade, West Indian Nightshade, Common Nightshade, Black Nightshade.

Here are photos of Physalis pubescens. How do the flowers and fruit compare?

http://www.wildflower.org/gallery/species.php?id_plant=SOPT7

https://gobotany.newenglandwild.org/species/solanum/ptycanthum/

Should I just pull this plant?

That's up to you. But eventually the fruit will ripen and there will be viable seeds, meaning that there will probably be more next year.