>How do we know we're not supposed to follow the old testament laws?
That's well-covered in the Acts of the Apostles, and in Jesus's own words. I'm sure someone will jump in to explain all this, though I'm a bit ill at the moment so I can't summon the effort to explain it all.
>Are there parts of the bible that has Jesus words directly from him and can I see just those somewhere?
Yes, in fact there are some Bibles where Jesus's words are printed in red ink to highlight them. This gave birth to a movement in Protestantism called red-letterism, which tried to put specific emphasis on the Saviour's words so I'm told.
>Why is the Bible so confusing, and why does it have some parts that feel random, like "so and so beget so and so" on and on.
All the begettings are genealogies. Ancient people used these records in order to locate themselves in time, much like how we use a numerical system, but it's only a rough guesstimate that people used before accurate record keeping. In the old testament, for instance, people used to mark the time by the regnal year of the king. So someone writing in "the 25th year of King David" would have made sense to people then, as much as it makes sense to us to say "in the year 1998." Technically, Christian/western calendars are actually following this same old way of remembering time, except that we go by the years of Christ the King, rather than the reginal years of any temporal ruler.
In law reporting until recently in the UK, statute books would be printed by regnal years too. This does make it very confusing. For instance, to go searching for a book of statutes from 1905, then you would be looking for a book labeled (Ed VII, 4) (i.e. statutes passed by parliament in the 4th year of the reign of king Edward VII, this is then abbreviated into Ed VII, 4). This is the trivia only a law graduate would be so unfortunate as to know.
Anyway, the point is that the Bible contains all kinds of stuff that had significance for other people, such as genealogies, such as "Adam and Eve begat Cain, who begat, etc."