I'm not sure of your question. Are your seams crooked or are your seams not meeting?
Either way, there are two factors, cutting and sewing.
On cutting, make sure your ruler doesn't move when you make your cuts.You either need to use a non-slip ruler (Creative grids makes some.) or use something on the back that will help you keep the ruler from slipping. Things I've used include Nexcare tape (a surgical tape), invisigrip (sticks on the back of your ruler) and that sticky shelf lining. Watch a couple of youtube videos on cutting will help you considerably.
On sewing, I use a stack of blue painters tape to mark my quarter inch all the way past the feed dogs. I think it's Bonnie Hunter that suggests using a piece of plastic (I think she said it was a hotel room key.) to mark that quarter inch line. It give you a guide that you press your fabric against and keep it straight as you sew your seam.
The best video I've ever seen o
n piecing is by Donna Poster. I think she has probably retired by now, but she left us some great videos on quilting.
The second quilt is easier. Keep asking questions. The folks here are generous with their advice. Keep watching you tube videos on quilting. There are some great free lessons there.
bkay