How to add non-standard Asian characters in private use area

I am totally new to Glyphs and am trying to figure out if I could use it instead of Fontlab, which I have used in the past.

For my character etymology research, I have been creating non-standard Chinese and Japanese character elements. In the past, I have added these to the Private Use Area in the font. To be able to switch to Glyphs, I need two things:

(1) Import Chinese Traditional, Chinese Simplified, and Japanese fonts into a single unified font.
(2) Place glyphs created in Illustrator into the PUA area.

I don’t even see how you access the private use area. It is not listed on the side the way Japanese and Chinese is. Also, how would you import multiple fonts so that they can be merged? If I am missing a critical tutorial, please let me know, but the PUA info I saw was not pertinent. Thanks.

You simply create new glyphs in the PUA. Read this please: