Armor Class: 17
Hit Point Maximum/Current Hit Points: 38
Multi-classing:
You gain the hit points from your new class as described for levels after 1st. You gain the 1st level hit points for a class only when you are a 1st level character.
As a Sorcerer level 1 your max HP is 6 + your constitution modifier: 6+3=9
Draconic Resilience for the Draconic Bloodline gives +1 HP per Sorcerer level so your Hit Point Maximum is now 9+1=10
As far as the feats go, I typically use them differently but if you were to use them as described in the PHB you don’t yet qualify to take a feat. At certain levels your class gives you the Ability Score Improvement Feature (this happens at level 4, 8, 12, 16 and 19. You cannot improve an ability score beyond 20 using this feature)
So currently as a level 1 Sorcerer your max HP is 10. A Warlock for level 2-3 gets 1d8 + your constitution modifier per warlock level after first (you’re a Warlock level 2). If you rolled the max, 8 you would have 8+3=11.
So your sorcerer HP is 10 and your warlock HP is 11. They do not combine. You only get the 1st level HP when you are a 1st level character, while you are a 1st level Sorcerer you are considered in whole to be a 3rd level character. You can take whichever of the two class HP maximums is higher but they do not stack.
Sorry it took me so long to get back to you on this, I had to do some research.