Both of these links are created using an Anchor, which is a marker on the page that a corresponding link points to.

Your second request is easiest to do, so we'll start with that.

1. In the article, scroll down to the paragraph that you want to link to, click at the beginning of the paragraph, and the click the Anchor button. In the Anchor dialog, type in a unique name for the anchor, and click Insert. For example:



2. Now that the anchor is created, scroll back up in the article to the place you want to add the corresponding link. This will be the link the viewer will click to be directed to the anchor. Select some text for the link, and click the Insert Link button. In the Link dialog, select the name of the anchor you created from the Article Anchors list, then click the Insert button.

To create a link to an anchor in a different article:

1. First create the Anchor in that article, in the same way as you did in step 1 above.

2. Then, in the article that is to contain the corresponding link, select some text and open the Link dialog.

3. Now, instead of selecting the anchor from the Article Anchors list (this list only displays anchors in the same article as the link), find the article using the link tree display in the Link dialog, then select the correct anchor listed underneath the name of the article, and click the Insert button, eg:

I asked another question Sun and Mon, about spacing on mobile but it hasn't been answered yet.

The other question you have asked recently, I have already answered - https://www.joomlacontenteditor.net/support/forum/101697