I do NOT recommend starting at the beginning and trying to read through.
Depending on your background and knowledge of Christianity and such yo might choose different approaches but the one I recommend is this…
My suggestion is that you read the Gospels first. Since it will be right at Christmas time, you might want to start with “Luke” since it has the Nativity Story in it. Well actually both Matthew and Luke have nativity narratives, but Luke’s is the more “Traditional” version.
Anyway…Matthew Mark and Luke are what is called the “Synoptic” Gospels and follow a more traditional “chronological” format. John’s Gospel is very beautiful but is more of a “prose” style. Doing this will give you a good grounding in Jesus incarnate life, death and resurrection as well as many of his miracles and teachings.
I would then recommend reading the Acts of the Apostles. Through this you can get an idea of how the early Church spread, some of the problems encountered, missionary journeys etc.
The letters (Epistles) will contain much teaching from the Apostles (mainly Paul) and supplement the Gospels very nicely.
The one book in the NT to avoid (for now) is Revelation. It is a book very difficult to read and understand.
Now - for the Christian, the OT can be viewed primarily as"background" for the NT. In other words, everything there points forward to Jesus and Jesus fulfills that which is prophesied in the OT.
Besides the prophetic books, the OT contains a lot of history…which is good to know but as I said earlier, this can be difficult to get through…and if you primary interest is in what is required of us now then the NT - not the OT - is the place to start.
My personal favorite book in the Bible is Matthew…
Peace
James