If I have cataracts that are not even in the advanced stages, will glasses improve my vision?

Yes. Glasses will improve refractive error (near or far sighted or presbyopic) if the cataract is mild. As the cataract matures, you may become more near sighted at first then notice clouding of the vision.
Possibly. Early cataracts usually don't affect vision that much, and even if they do cause a prescription change, it is often corrected with a new prescription for glasses or contacts. Glare and color changes, etc. Can't be fixed by glasses however.