Notes:
Watercolor is about learning to guide and control the water. The water is the key. The way to learn this is by practice and getting a feel for it. Different things happen with different amounts of water.
Use good paper. In my opinion you can use slightly 'lesser' paints and brushes, but good paper is essential. 'Lesser' watercolor paper does not let the water and paint flow and can be like painting in sludge. I use my 'lesser' paper for other mediums such as colored pencil, gouache, or acrylic
When using salt, put it on when your paint it still wet, but not soaking (the paper will be shiny with no puddles). If you put salt in a puddle it dissolves and does not make a texture and then you have to scrape it off after it's dry.
I do not spray rubbing alcohol much, but try it as it makes interesting textures and shapes.
My basic palette of colors was chosen because the colors are very transparent and mix well. My basic palette is quin. rose/perm. rose, cobalt, aureolin, perm. alizarin, indigo, new gamgoge. I also often add burnt sienna, viridian, ultramarine/french ultramarine, pthalo blue, pthalo green, green gold, and sometimes sap green although I can make so many green with my palette colors. There are many other colors I use as well, but these are the ones I use the most. Try colors when you can and find the colors and mixes you like. I really like a lot of the quin. colors (quincridones), they are lovely and I may some day do an entire palette with only quin. colors on it.
There are many ways to paint with watercolor. The most basic and the one that is best, in my opinion, for learning to control the water is the value study painting using one dark color only. I learned by doing this long ago and continually return to this way of painting to keep my skills sharp (and it's always pleasant for me to paint this way). I either use the painting as is or it becomes an under-painting and I add other colors on top with washes and glazes. I also suggest painting with complimentary colors and then three primary colors as practice (you can change the primaries in different paintings).
My basic method for painting is to start out very wet and get more and more dry as I progress. My first pass or two are most often wet-n-wet (wet the paper and drop the color onto the paper). I like to get my basic shapes and values in place and let the watercolor 'do it's thing'. There are textures and shapes I can not get without letting the watercolor flow and acting as a guide. Then, I take more control (a little less water) and shape the painting in the middle set of passes. I add color to dry paper and move it where I want with a little water. The last few passes over the painting are very dry and basically I am drawing with the paint as I add and/or subtract to get the details. Dry brushing is using a slightly damp, almost dry, brush to apply the pigment. I do not often dry brush but use it most often for fur, hair, etc. Remember - the paint will go where there is water.
The way I learned watercolor was to take different classes and workshops when I was able. I also used books from the library and online tutorials. Every teacher and artist has a different approach to watercolor. I use what I like from each class/artist and make it my own by incorporating it into my work. Many of the things I learned I do not use often, but it is fun to try something new.
Be true to who you are. Take what you learn and make it your own - fit it into your style and personality. If you are a more detail oriented or controlled individual then that is how you may paint. You may prefer to work with paint that is a little more dry and add many details. If you are a less controlled or more experimental person you may paint mostly wet and add less details. Both ways of painting are beautiful. Always try everything when you take a class/workshop, but then make it your own. Art is about self expression - put 'you' into your work (this took awhile for me to be able to do...). Art is supposed to be enjoyable with a very little dash of suffering, lol.
In a group or class there will always be beginners and more experienced painters. Some may have lots of drawing experience (which helps) or experience with other mediums. We have ALL been beginners at some point and remember how hard that can be. We all struggle as we work to improve and it is a process and happens at different speeds and at different times for everyone. Do not 'judge' your improvement by looking at others as that actually tells you nothing - it took me awhile to figure this out and to only look at how much I have learned and improved. There will always be people who can paint much better than I can which is great because I can learn and grow from watching them and working to improve my own skills and voice.
Happy Painting!