Conference pear will sometimes produce pears without a cross pollinator, but I suspect yours will need a companion to give you fruit.* You should find this helpful.
Here's some info on pear diseases so you can see if any of it fits what you see on your tree.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.