I have been painting for over 40 years, primarily in watercolor. As you might guess over that period of time I have settled on a few items that I feel most comfortable with. Every time I do a workshop, the attendees want to know what my preferences are. I should say that I am a creature of habit, and many of my choices are based on what I was taught early on. My advice to you is to choose good quality materials of any brand. Student-grade is not acceptable and will slow you down, rather than help you get started. All the materials are available at my local art supply store, A Passion for Painting, in St. George Utah.
The best watercolor brushes are Kolinsky Red Sable. The hold a lot of paint and maintain a good point. However I prefer to use mostly synthetics, because I like the firmness and feel of the brush. I use Aquarelle 1-inch flats, and rounds in various sizes. I like Loew- Cornell 7020 series brushes a lot.
There are lots of fine watercolor papers and I have tried many of them. But I have to say that I always return to Arches 140lb and 300lb cold-press papers. Arches is very durable and will hold up to lifting and wiping and multiple glazes. It comes in regular and bright-white. I prefer the brighter paper. Make sure you buy 100% cotton archival paper. Do not buy any of the student-grade tablets. They are junk and will sabotage your efforts.
For mounting my watercolor paper I like using “Incredible Art Board.” It is like Gator board or Fome-core, but the surface is stiffer and will not curl or bend. The inside is foam, so it weighs almost nothing. I like to tape a matboard flap over the top so I can protect my painting and carry clean sheets when I am outdoors. Tape the edges with white artists tape to protect them from cracking. It can be cut with a razor blade to any size.
There are lots of fine watercolor palettes out there. I have used Eldajon palettes for over 30 years and like them because of their three deep wells. I don’t like flat palettes. They also fit easily into a backpack, or my Sienna pochade box.
I use Daniel Smith paints almost exclusively. I started using them many years ago because of their attention to lightfastness and quality. Then I got hooked on the Quinacridone colors which are marvelous. Now most paint manufacturers have quinacridones and the quality is better all around. Again, do not buy student-grade paints even for practice.
I have used this little watercolor travel set from Windsor Newton for many years. In fact I own about 10 of them. It fits easily in my carry bag and I can hold everything in one hand. It is the epitome of portability. I have never been on a painting trip to Europe or anywhere without it.