I'm kinda with you. Haven't been writing in my diary as much these past few days because I'm sorting things out, cleaning, finishing up my semester :/ I feel good, but it's a little annoying

Prismas are expensive but I really like them. For pens, I use either ballpoint or .05 & .005 pens. I like microns, but you can find cheaper :-) If you like pencils, I'd try a prismacolor ebony pencil

if you aren’t using wet media (like watercolor), i think basically any sketchbook will work perfectly fine for you. like vashti, i really like sakura microns, but ballpoint pens are more universally useful, i think (and much, much cheaper), and come in multiple colors.

if you did want to try watercolor, though, it is a lot of fun for doodling and my favorite medium! the canson mixed media pads are cheap and work well enough and you can pick up a cheap set of watercolor pans pretty much anywhere. if you don’t care about lightfastness or potentially chalky paints, any set you get should be fine. whatever you end up doing, hope you enjoy doodling! ^^

tbh for doodling i think whatever is easiest available for utensil, even just pens or pencils you find lying around. for sketchbooks i like canson branded