How to machine piece a quilt
Firstly, if you are a complete beginner, familiarise yourself with your sewing machine. Read the manual and have a play on some scraps of fabric.
It doesn't matter what kind of machine you use. A simple mechanical one will work perfectly.
Use an 80/12 or 90/14 needle. Your machine will probably come with one. Cotton thread is best for quilting in weight 40 or 50 but if you only have polyester that will be fine. A neutral colour is fine unless you have very dark fabric where you might want to use black or a darker colour.
If you are using a pattern, read through your pattern carefully. Lots of them will have helpful tips too.
Machine piecing a quilt relies on you having an accurate seam allowance so cut your fabric out carefully. You will use the edge of your pieces to guide where to stitch.
Using a rotary cutter (and cutting mat, of course!) is the best and quickest way to do this. Remember to square up your fabric regularly to get accurate cuts, especially if you are using a smaller cutting mat and need to fold your fabric to fit it on. You can also manage fine with scissors if you are very careful. I'd recommend drawing on your cut line precisely with a fabric marker if you're going to use scissors.
Now you are ready to sew. Quilting generally uses a 1/4'' seam allowance so stitch your seams 1/4'' away from the the edge. There are different kinds of stitch guides or 1/4'' presser feet you can buy for your machine but nothing beats using the markings on your sewing machine plate and practise. Your basic zigzag foot that comes with your machine is perfect for this.
Follow the order of the quilt pattern when constructing your quilt.
Use any stitch length that suits you, I like to use 2.
Go slow. Don't be afraid of mistakes, they can always be fixed and are an opportunity to learn what works best for you. You can do this!