If you want to quote the beginning of the article, you just drop the whole link in, like this:
https://forum.makerforums.info/t/new-to-k40-start-here/79751
Note that this doesn’t really preserve much formatting, as see above.
If you want to link it in text, you can just say to start here with [start here](/t/new-to-k40-start-here/79751)
To make it possible to link to a heading inside a post:
<a name="the_id_you_choose"></a>
## [Name Of Your Section](#the_id_you_choose)
Then the link would be [text](/t/category/id#the_id_you_choose) and it will take the user directly to that heading. (The number of # characters determines the level of the heading.)