how to start painting?

Like with anything else, don't do it all at once.

Maybe write down your ideas so that you don't forget them.

I keep an extensive journal of ideas for future drawings and paintings. Practise every day. Draw and play with color. Many people dont start with ideas for their work and many do. (I always do several sketches , then a quick watercolor or pastel of my drawing. I usually work from life so Ill take photos and Ive only recently learned taht using my photos from the copmputer screen rather than printing them, infses the reference photo with more light and reality.

I practice perspective almost every day whenever I get a moment free. (I get my sketch books at a printers discard box where the hand bound sketch books that are made for the Uni are tossed). These are really good rag paper books that may have just a scratch or a slightly bent cover. I get em for like 50 sheets for 2 bucks. (A real bargain and I get all kinds of surfaces)

I went to the local Y and took a drawing/painting class. It was not only helpful but fun.

I rarely start with ideas; that would be too intimidating. I prefer to just start painting, usually a foundation of weak or vague colors and shapes and let them tell me how to alter, eliminate, and develop them. Freedom and fun--or maybe I should say expression--is what that is about since what the painting tells me to do is, I suspect, most often my subconscious working as my guide. In a way it is me and in a way (relative to my ego) not me.
Nevertheless, the paintings usually get done and turn out better than I expect--but not as good as I hope for.

You are one of those wherein the act of painting itself is the art. The subject emerges with your work. However, I submit that each stroke you paint, limits the next strokes to fit within a more finite range of color and shape options. Yor paintings evolve whereas mine go to apredetermined completion.

Ill bet I throw away many more paintings that dont please me. I will paint something against a Platonic "reality" and my work must measure up or I dump it in the bin and it becomes kindling.

Hobby is the combination of freedom and interests. Painting will rich your life colorful, just keep your passion and original intention.

Start from the sketch, go buy a sketch pen, draw a square, triangle, round, be sure to meditate. The beginning is to keep copying, has been copying, you can draw all the things from the book, and don't draw the physical things that will lose own self-confidence.

Totally agree..

I like painting, too, and start to draw painting recently. At the beginning, I draw easy staff such as eggs and boxes with pencil.

I think it is not necessary to paint it all, which costs a lot of time. Just do more practice.

It's hard to paint it all. You can choose one and paint it in your best.