I love this question because I am also a diary giRLIE and I love writing in it every day especially when it comes to planning out my days (cuz I am ESFJ hahaha). But let me try to give you some phrases so you can get the hang of the grammar form for diary writing :)
To answer your question about making breakfast, this is how I would write it in Korean:
8am - 아침밥 해먹기
The form is different! So if you wanted to say something like “take a walk” you wouldn’t write it like 산책해요, you would write 산책하기!
Another example would be if you want to write “draw” you wouldn’t say 그림 그려 you would write “그림 그리기" Hope that makes sense 🙂
HAppy DiaRY-ing!!! 😍