just for reference, you get 3 skill points per extra level that you gain through normal xp earned for level ups.
so 3*19=57 skill points. on top of the free skill you get to choose at the start for a character, you then add them on as you wish during play (i recommend check a few descriptive build guides out if you don't understand skills much as they often give good reason why some skills for 4th 5th and 6th rank skills are chosen over the other.)
As for cards from packs.. yes you can go from RANK I to RANK XX now, but rank I-X gives you either armour customisation options on odd numbered rank cards and skill points on even numbered rank cards. For XI to XX cards, this just boosts bonus stats and those stats are not always entirely helpful to all build types .. so you may find some of them useless tbh.
Also sadly APEX rating is also calculated from the opening of packs too, which is why these people who pay real money to buy massive amounts of packs have such high apex ratings. (How on earth someone with 7k apex rating had a batarian scrapper XX is beyond me considering the RNG and the massive loot table now.. but meh.. if they are going to be stupid enough to pay that kind of money out then more fool them eh 🙂
