Welcome and you've found a great place to get lots of good advice.
I'm of the "pre-wash, iron/starch" group, but it depends on a few things. Some of us have had a bad experience with bleeding/shrinking fabrics and prefer a flatter quilt after it is washed. Others really like the puckery look of a quilt after it is washed, when the fabric hasn't been pre-washed. All personal preference.
My advice is this: be very careful with accurate cutting and learn to fold your fabric "on grain" before you cut it. Leah Day has a very good video on this. Otherwise, other QB posters have covered a lot of ground for you already.
Another tip: Love your fabric. You have to look at it for along time.
Have fun and be sure to post pictures.
Watson