Hey! So happy to hear you’re diving in to watercolor. You’re going to have a marvelous time. Here’s a response to this same question I did a couple years ago; it all still holds true:
Advice 1: Start today! Go! Quick march! Pick up some supplies at a craft store (even Walmart carries decent paints and brushes), and start making a mess with them tonight.
Advice 2: Experiment heavily and find different ways to manipulate the watercolor paint. Mix it with coffee instead. Paint it on dry paper and drip alcohol onto it. Sprinkle fresh paint with salt, sugar, or cover it with tissue paper. Try food dye. Mix it with Crayola markers.
Anyone else have suggestions? Throw them in here!
Advice 3: Look at they ways other artists are using the medium. For example, artists like Tony Sandoval, Dave Mckean, or Florian Nicolle use watercolor for vastly different subject matter, but they create new effects through mixing watercolor with inks, graphite, or opaque paint. Take influence from other artists’ work and try out what they’re doing :) It stretches your boundaries!