Based on your question I'd assume you are fairly new to archery. If so here's my advice. Take your bow and go to an archery shop. Get the bow adjusted for proper draw length.

Then you can pick arrows. How long depends on the bow's draw length and the position of the rest on the bow. I would recommend arrows the same length as the bow's draw length. You might be able to get them shorter, but get some experience under your belt first.

Spine is the other important consideration. Spine is the stiffness of the arrow and must be matched to the bows draw length and draw weight. That's why I recommended going to an archery shop.

As for broadheads? Everybody seems to do this, but unless you are planning on going hunting in a week or so you don't even need to worry about them. If you are planning on hunting next fall then you don't need to worry about broadheads for at least 6 months.

Learning how to shoot, learning good shooting form, how to tune your equipment and adjust it for you will keep you busy enough for a long while. And field points is what you use to practice with to do all this.