Can I try it out using Fleece as a backing or is it best when using a cotton backing???

I have used cotton when I started and have done some flannel.
I made large blocks about 14 inches, then started meandering on the fabric. After awhile I tried making hearts, etc. I have these blocks by my sewing machine to check my tension before doing one of my quilts now. I've done 5 baby quilts with free motion, now building a quilt frame so I can go bigger.

I'd suggest starting with cotton since fleece is a little stretchy which can add a little complexity. If you don't want to start on an actual quilt, make sandwiches out of excess fabric...14 or 15 inches square, or even fat quarter size, then practice away. Using the small size makes it easier to learn, I think. Once those pieces are filled, you can trim them to make them into a tote bag or other item, so the fabric and work is not lost.

Thank you Noreen and Kate,that's a lovely baby quilt, I will give it a go and that's a good idea to make up peices to use as a bag---hate wasting trial peices

I do FMQ and I always practice on the extra peices for the guilt I am doing. This includes the batting, top and backing. This is to check my pattern and also tension of machine.

I think you will be much happier if you begin with cotton.

Campion, start with cotton, it is less expensive & a good way to start practicing.

Norene, please post a picture of your quilt frame when you get it done.

start with small practice pieces to get the hang of it...pot holders/place mats are a good size to start with. it takes practice. if you start small it will be easier to build up to larger and larger. some people do quilt large, king size quilts on their regular machines...
practice, practice, practice

thank you all for your advice---I have tried a small peice but am not very happy with it,it's ok to make into a tote bag I think!!! I did use cotton and not fleece. It was interesting to do.

Don't get discouraged. It takes lots of practice.