confused about size for for printing

I know this questions probably gets asked quite a bit but I am confused by it all.
What is the best page set up if I were to want to print at a maximum of a3 (I usually paint in square sizes).
I use sketch book pro and I am new to art rage.
I don't fully understand the sizing when painting but I had most paintings set to 300dpi, which I recently put up to 800, at 5500px X 5500px. I don't know if that is way too big for my needs (I prefer to be careful) or not.
On art rage it confuses me more, you have page size and print size and dpi (or PPI, that confuses me too lol). The dpi doesn't make things slow but the page size does.
What page size for a decent quality print? I'm sorry if this is an annoying question, I used to the the simplicity of digital painting until sizing came into it :-D thank you

Hello normie and welcome to the ArtRage forums:)
Yes this question has been asked once or twice before:p

Whilst a painting is still “inside” ArtRage (or any other paint program for that matter) PPI/DPI is irrelevant, as there are no inches inside a computer!
(In very broad terms DPI is only needed by the printer so as to know how close together the ink dots need to be.)
However canvas pixel dimensions are important as you need to have enough pixels to meet your viewing/rendering intent for the finished work, i.e. for print close up (book), print close to near (wall picture), print faraway (poster/billboard) or web based viewing.

In the real world I too always favoured A3 as a drawing size and still find myself setting up canvases in AR more or less to the digital equivalent, approx 4950px x 3510px. Assuming 300px per inch when printing, that will print out in the real world to A3 with no loss of detail.
(Also from a practical view point I find that on my computer things can start to lag too much for my liking with canvas size above 5000px².)

The ArtRage website has a page on things to consider like PPI/DPI when setting up a canvas: https://www.artrage.com/choose-canvas-size-artrage/
You may also want to have a look at this site which has some useful general information about what is needed pixel wise in digital art and when and where it matters: http://www.tutortanith.com/imagesizing2.htm

On a side note, if printing is your intent then knowing how to set your zoom level within ArtRage so you can see your painting on screen 1:1 as you work can be very helpful.
If you don’t know your screens resolution then this web based utility will tell what it is: http://pxcalc.com/ (Note, this site calls it DPI but in reality it is telling you the PPI)
So to find the zoom level, divide your screen’s native resolution by the ppi you have set for your canvas = screen zoom level.
Examples based on my 15.4” screen:
Screen resolution 129px / canvas ppi 300px = 0.430. 1:1 Zoom level is 43%
Screen resolution 129px / canvas ppi 72px = 1.791. 1:1 Zoom level is 179%

Thank you for the helpful information, markw 😊