Did you register before the 21st? Tbh its only a day early anyway, so your not exactly missing a lot! Think its open to everyone today.
Its good, feels a bit dumbed down, kinda like SWBF. not the same gun mechanics as BF4 or 3 which is a shame, but they still might change it.
The map is ok, not as good as the one in the closed alpha, that was a great map! This one is basically a desert.
Check out these vids for a bit of a starting guide.
Feel free to add me on Origin - MessiahComp1ex