Use the markdown
When editing/answering/questioning on the desktop version you can see a little help/question mark button at the top right corner of the field where you write something. This gives you plenty of information about how to write stuff in posts on the site.
Please do not use HTML if there is a way around it - HTML regularly messes with the markdown. Try to get used to using MarkDown without the features (at least as a workaround).
Here is an example fo you with the links:
You can write a link to the MarkDown help the following way:
[the MarkDown help](https://worldbuilding.stackexchange.com/editing-help)
In the same way you can accomplish
This would be accomplished like this:
- a list
- in multiple ways
For a numbered list
- which would
- look like this
you would write:
1. which would
2. look like this
A header is
# Header level 1
## Header level 2
### Header level 3
And emphasis is
There are quite a few more things that you can find in the linked help menu. If you are regularly posting stuff it's worth it to try and learn it. It makes stuff a lot faster and easier if you don't have to rely on the little buttons.