Help with baby bootie pattern

I am making these roll-top baby booties

And I don’t quite understand knitting into the front and back of each stitch…Do I mknit into the front, like normal, but keep the stitch on the left needle and knit into it again?

Also, this pattern doesn’t mention stitching this bootie together… Will I need to do that, from the looks of the pattern?

Thank you!

Yes, that’s how you do kfb. Yeah, the instructions are a little sparse, but I think you’d sew it up. When you get it finished, it ought to be obvious where to do it.