"Morning Pages are three pages of longhand, stream of consciousness writing, done first thing in the morning." — Julia Cameron
Seven words into her description of Morning Pages, Julia Cameron says that they are done longhand. Pen and paper. There are many reasons, but the most important is the most primal: writing with pen on paper is as close to natural as writing can be. Writing by hand is simple, close to the bone (literally), and the way we first learned to write. (That last may have changed in recent years I'm sorry to say.) Morning Pages are on the desk, receiving ink from a pen held in the hand which is moved by the mind. The action is immediate, permanent, personal, tactile, private, individual, and traditional. Remember that tradition doesn't mean that something is just old but is so tried and true that it is passed down through the ages. I've been through at least ten different word processing programs and at least double that many file formats (some of which are no longer readable by any machine I can access), but the paper and pen I use could have come from my childhood or my father's childhood or his father's and so on down the line.
Morning Pages are analog and that facilitates connecting with the stream of words that flow within us but which is too often blocked by embarrassment, worry, or inconvenience. The fewer things mediating between thinking and writing, the better. If I have to boot my computer, if I need access to electricity and the internet, if I'm unsure the machine is saving my files, then I have that too much between myself and writing. If instead, I have a stack of blank pages waiting near my desk and a pen on hand, I'm ready to write Morning Pages.
There is plenty to say about what pen to use. Mine is a Lamy 2000 fountain pen with a medium nib that I fill with Noodler's blue ink. That wasn't the pen I used my first day of Morning Pages, but I got there eventually. Choose a good, fast pen that feels great in your hand. Don't spend money on one. You have a pen already. Use that and go from there.
As for paper, again, start with what you have. I write on used paper. I print lines onto the back of used sheets and it works well for me. I suggest that you choose paper that allows for 750-1,000 words of writing over three pages. That feels like just enough.
Simple tools. That's all you need. Keep electricity and the network out of it. Do this personally, privately, maybe even secretly and keep the process completely analog. Get back to basics and you stand a better chance of getting back to yourself and into your own words.
Be open to all the ways in which you might do your best work. THat may begin on the computer. I started there too. Eventually, the necessity of going analog impressed itself upon me and I moved into that because it showed me things I couldn't learn on a computer. Find your way and accept that it will change over time. My way is analog and that's what I suggest to you. Now go make your own choices.