Texture painting blurry?

Ok,did some reading and might have found my answer ,but still have a question or two? I’m making a landscape and having issues with texture looking blurry up close. On a thread I seen on here. Somebody painted with a image that was 2000 x 2000 and made the texture within blender as 4096 x 4096 and got decent results. Does the texture size within blender matter more than painting image size?

1: What size image Is best for texture painting?
2: What size should I make my “new” texture in blender?