Mark is a short account of the life, ministry, and claims of Jesus
Mark is dramatic, profound, and brief. It can be read in one sitting.
I recommend reading Mark from a print copy of the Bible. The English Standard Version, the New American Standard Bible, and the Legacy Standard Bible are excellent translations.
You can also read Mark using an online Bible application such as BibleGateway, or you can use the Bible Project's Bible reading application.
I suggest reading Mark in one fell swoop; that will give you a unified understanding of the entire book. However, if you can only read smaller chunks, then try reading it for 15-30 minutes a day.
By the way, if you want to get as much out of the book as possible, I recommend a strategy used by a well-known pastor. He reads a book of the Bible once a day for 30 days; usually, he identifies something new each day that he did not see the day before.
Enjoy your study of Mark. If you have questions please ask me or your pastor.
Here are the first 2 chapters of Mark on BibleGateway.