Hi Mohammed, I wouldn't focus so much on a micro niche, but rather a niche YOU love. Here is how I help people choose niches: How to find your passionate niche topic and narrow down broad niches.

Here are some general niche tips.
A niche is something you feel super excited to write about, a skill you have attained, something that resonates with you. You will want to be focused on one niche. What is it that you want to help a group of people with or what problem do you want to help them solve (group could be age, gender, location, experience level, degree or type of need, etc.)

A niche is not a product, it's a subject that you can help a target audience with. Remember, you are not setting up a shop (store), you will be writing lots of articles about your niche to help your targeted audience.

The importance of a targeted audience is that It's always better to target a specific niche with a specific solution to problems.

Kyles asks us to complete this statement.
'i want to help ____(group) with ______(problem)'

For example. I like camping and what to help campers buy the right equipment to make their camping experience more pleasant and safe.

Camping is a very broad topic with a lot of competition so to eliminate some competition in the beginning so the website has a chance to grow, the focus needs to be a smaller scope. For example essential camping equipment for beginners. I can talking about camping, my experiences, what I have learned about camping, and how I have found good equipment and what I believe is the best equipment. Once the website is established and has a good volume, its scope can be expanded to include other things camping related. This is just an example.

Learn Questions People Ask About Your Niche.
https://www.usetopic.com/people-also-ask
Use tools like the following to see questions you can address for your niche.
https://soolve.com https://answersocrates.com https://usetopic.com/people-also-ask and Google search scroll down and find "People also ask section" or use Quora.com
Why should you narrow your niche when first starting?
The key to getting started fast is to narrow your niche down to a specific topic. This way, you will eliminate a lot of competition and get results much faster. Once your site is established and you are getting traffic you can expand your niche scope.

Here are a couple of blogs on narrowing and expanding a niche.
How to narrow a niche down How to find your passionate niche topic and narrow down broad niches. How To Expand Your niche later Succeeding With Golf Balls, Scaling With Shoes! Once a site starts gaining traction, traffic and authority you can then scale to cover another subcategory.

The best niche is the one you are most passionate about, know something about and can help others with. People search the internet for help and solutions to problems. If you website provides help and solutions and your content is original it will rank well and it will be presented in the search results.

You can find out if people are searching for it by doing google search - watch for the autosuggest keyword extensions as you type.

WAs keyword tool, Jaaxy will give you the average number of searches a month plus the competition and search engine optimization opportunity.

The numbers grid for understanding Jaaxy results is
AVG more than 30
QSR *click get QSR" less than 100
SEO greater than 94 for new websites.

The training will help you to understand all of this.

We noticed that you are a teacher -- what is your subject matter or grade level?

Depending upon your subject and grade level there are affiliate programs for courses and of course there are always books, videos, games etc.

You can find what affiliate programs are available for you subject area or age level or both doing a google search.

your idea + affiliate program + location (location is optional).

For example.
algebra + affiliate program + Middle East.

It is also very possible you can publish your own materials.