Q.Blueberry Only Flowers On 1/4 Of Plant
The flowers only appear on branches that grow from two stems all others are unproductive. Pic 1 is the bush Pic 2 are the productive stems Pic 3 are the unproductive stems

Certified GKH Gardening Expert
Those stems will be productive next year. As the older branches become unproductive, it will be necessary to cut those off leaving the 2 year growth.
This article will help:
https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-plant-pruning.htm
This article will help you to feed them so that they are most productive:
https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-fertilizer.htm