GUI - Insert text into blank field

Please provide an answer with me using the GUI.

I am having a hard time inserting text into a blank field.

I use "Remove Fields" to clear out unwanted data. I then try to "replace" the empty data with text. For example I try to "Replace" "Genre" (which is empty) with R&B (or any other genre).

When I try this, I leave "Original" empty, 1space, two spaces, . *? nothing works.

I know I can create a text file and import the text file into the "Genre" field, but there has to be a simpler way other than creating a text file for every Genre, Comment, Year, etc..

Thank you for your patience, I am becoming very familiar with the program and love the convenience it provides me.

I have searched for empty fields, replace blank, and have found nothing relating to this subject.

True. You simply enter the data in the field and that's it.

If you have several files that should get the same data, perhaps because they belong to the same album, then select all these files in the files list.
Now enter the correct data in the tag panel in the corresponding fields, e.g. "Pink Floyd" as ARTIST and ALBUMARTIST, "Animals" as ALBUM, 1977 as YEAR, "Electronic" as GENRE.

Now press Ctrl-S to save the modifcation. Done.

Thank you very much. I didn't know I could modify multiple files in the tag panel.

OK: if you want to modify only a single field in a single file (e.g. TITLE), it may be easiest to do that in the files list:
Navigate to the correct line and column either by mouse or by and .
Enter the date,
press .
Done.

And to make matters even more "complicated":
Sometimes it may be necessary to enter data in a field that is currently not displayed, neither in the tag panel nor in the files list: for this purpose, there is also the extended tags dialogue (Alt-T).
In this dialogue, you can either modify existing fields, delete them and/or add new ones.

Perhaps you also check out the help on modifying the tag panel
https://docs.mp3tag.de/customization/tag-panel

and the columns.

https://docs.mp3tag.de/customization/file-list