need some advice as beginner

Do not quit your day job. 

It's estimated that you will need a diverse portfolio of 6,000 or more assets before you can expect to see a steady passive income.

The amount of time required to create a high quality portfolio will depend on you.  It could be a few months or a few years.  Learn from your mistakes. Keep learning new skills. Try new things. 

As already stated there are no answers to your questions. You need alot of quality assets that are in high demand. What kind of passive income are you expecting? At .33 cents / image, imagine how many sales you need to earn $100.  Approximately 300 downloads. How many assets are needed before there are 300 downloads. Probably several, several thousands. It is a slow process and requires alot of work. 

You need a lot of assets that are in high demand. The problem is to get the answers from your crystal ball. Nobody can tell you what sells well, except Adobe. They do in their blogs. You need to check those.

But do not think that stock is a machine to print money. That would be too easy.

These are all extremely difficult questions to answer, as it is different for every contributor. Firsts of all, when you're talking about stock, the idea of a passive income is a myth. While you might be making earnings on some of your submissions, you're also busy photographing or making and editing new AI assets in the hopes of further increasing sales. Creating in-demand assets on a regular basis is also a factor.

The one question I think I might be able to answer for you is that video is probably the way to go for maximum earnings if done well. The royalties are a bit more, and there is probably less competition. But even that is just an assumption on my part.

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.

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