Congratulations. Its a great idea to self publish.
Choose your desired outcome. Books are easy, but if you are interested in memoirs, do you want a paperback with a few images, probably black and white, or do you want colour photos principally, with captions to go with them? The former led me finally to Kindle Direct Publishing which I can help you with, whereas the latter led me to Photobox or the equivalent, of which I have little experience.
Charles Dickens refused to start writing until he had settled on a title. Interesting. A title is a tease, according to my friend Philip who is in publishing. Aim to entice readers.
Titles I admire include Zen and the Art of Motorcycle Maintenance (I have never read it), Future Shock by Alvin Toffler (I have never read that either) and The Use and Abuse of the Bible by Dennis Nineham (which I did read and found disappointing as the contents did not match the title to my mind). They all have an intriguing feel.
When writing her novels, Iris Murdoch would not put pen to paper until she had worked out the whole story in her head. Likewise Benjamin Britten composed his operas in his head, and then it was simply a case of copying out the notes. In contrast, some novelists start writing with an idea and see where it leads, e.g Tolkien, who wrote down In a hole in the ground, there lived a hobbit. He then wondered what on earth a hobbit was. I have tried both methods, and was pleased with the result in each case.
I am a mornings person, and get my thousand words done before anyone else is awake. Find your best time of day for writing.
Its worth thinking about the finished article early on, e.g. a paperback needs a good cover that draws the reader in. This may require a photo of yours, and its good to get that sorted sooner rather than later. The actual photo you end up with might affect the text. At Readers Digest, they dont find a photo to go with a story; the story is an extended caption inspired by the photo which itself begins the process.
To get a good outdoors photo, think about the time of day for the best lighting, weather conditions etc.
The cover for When That Time Comes was created for me by a graphic designer. Unforunately, the text goes within nine milimetres of the edge of the image as you can see. Amazon requires bleed on the edges to allow them to trim the book. To make this work without losing text, I had to put a border round the photo. You can see the effect in the second image. So in creating your actual cover image, make sure nine millimetres of the edge can be clipped off without loss.
Develop a sense of what is in Copyright and therefore needs permission, and perhaps a fee. I have a book of Clip Art with thousands of images in the public domain which has proved surprisingly useful.
For copyright issues regarding text and images, see ALCS | Copyright basics for writers . When you have published a paperback, if it has any circulation worth speaking of, be sure to join ALCS. I soon regained the joining fee.
For page two of your book, copy what other books do in terms of disclaimers and name of publisher, and add its ISBN number as well as it being on the barcode on the cover.
ISBN numbers cost money. They are the province of Nielsen. However, if you use KDP, Amazon will supply one free. Amazon also creates the barcode for you. No need to purchase them from Nielsen.
As regards the text, remove all typos. The bane of my life! You can hire someone to do this for you if you want. They will probably charge per thousand words.
I use Microsoft Word to write a docx file, and then use Kindle Create which you can download free to make a file to upload to Kindle Direct Publishing (link at top of page above) and launch it in Kindle format. Follow through the steps that they give. See here for more tips on using MS Word to create your book.
I tried using a docx file for my paperback version but it was not a good idea. I soon learned how to create a pdf file from the docx file to upload instead, which is much better.
Have fun! Do ask for help.