Hi, - Welcome -
Have you done any other sewing?
Different types of fabrics can be put in one quilt - but they can be challenging - especially for a beginner.
Even some experienced quilters/sewers try to avoid putting stretchy and non-stretchy together.
I think the most important criteria is for all the components to be washable if you are planning to make items that will be washed at some time.
If the item is to be "looked at only" - then - I think - it may not matter as much. (I only make "washable" items.)