hi so i havent played 40k since the month before 8th edition so i need some help on how much my list costs! i dont have any rule books handy so ill ask here!

1 Farseer with singing spear

10 guardians shuriken cannon
5 avengers no exarch
2 x 3 wind riders with 1 squad with scats one with shuriken cannons
3 x warwalkers with scats
vyper with scat
wind serpent with lance
wraith knight sun cannon
crimson hunter exarch with laser lance and pulse laser
5 wraith blades with axes
and thats it!!
so how much points is it? and how can i improve this list!
and im not sure on how the points work.
do you add the points per model for say 5 and you have a squad of 5 of them so its 25 then you have to pay for the extra wargear? thanks!
and i reposted this post because i placed it in the wrong section!