What kind of easel is that you are painting with?

hi, what are some of the differences and challenges the artist have between outdoor and indoor? how to deal with people and not get them mess with the artist mind? i tried painting 3 times and i had extremely hard time mixing color, it went muddy to fast. the light kept changing and as i'm not proficient in mixing color fast i would be lost and didn't know what to do next. talk about the materials to carry.

Do you really need a diffuser/ umbrella for your plein air easel? What do you think are the best features to have in a plein air easel if you are painting in Watercolour? Do you have any suggestions for building your own plein air easel? I am trying to build one using a camera tripod. Also, Is it better to take a photo to help paint the shadows in accurately, start the painting with the basic shapes and then add the shadows in from the photo? I'm thinking about if the light or weather changes. Plein air painting always seems so spontaneous. How do you plan out your painting quickly so you can actually get to the painting part? Any tricks, tips or tools you can suggest for this?

I'm getting how to find the proportions of a side by side drawing. I found the Glasses very helpful, I'm still not clear on translating the size of things that are farther away onto the paper and how to make those things bigger or smaller than they actually are. Is that more about perspective? Sorry, I am an absolute newbie to drawing. I've learned most of what I know from youtube and have no formal art training. Thanks!