Need text box on some pages only

What and where are you trying to add text? What theme are you using?

I am very new to WP, and do not know the tricks. I am using “Alexandria” theme. I would like to put 2 links, preferably on the right side, but only on selected pages.

As in a widget? That would be the easiest way to do that – and you can define the widgets per page with:

https://www.ads-software.com/plugins/widget-logic/

YEs! Widget Logic will help. I see how to activate/deactivate widgets, but not how to add a widget.

General widget info:

https://codex.www.ads-software.com/WordPress_Widgets

If about the plugin, you can ask here:

https://www.ads-software.com/support/plugin/widget-logic

Actually, I downloaded Widget Logic Visual, it seemed better for me. I installed it as a plugin because I do not see how to install new widgets.
It shows up as a plugin, not a widget [not really surprising].
Do not know what to do at this point.