Don't be too hard on yourself if you are new to quilting. Practice helps and it has taken trial and error for each of us to get where we are today and where we will be tomorrow When quilting a sandwiched quilt a walking foot makes a world of difference. When stitching straight lines I use a piece of copy paper cut to the width I need and then place one edge against the seam and stitch along the other edge. I also use this method when stitching across a block and move it from from to block across the quilt. If I stitch into the paper I just through it away and cut a new piece of paper. Now that there are rulers for quilting you could use a ruler edge and do the same thing.