That is a nice box to start with!
You have two coins in this first box that are worthy of some bragging rights ... some observations from my data at 268,400 USA nickels searched ...
Your 1942 (Cu/Ni) coin is a relatively tough find ... I find one every 5260 coins searched ... that's one 1942 every 131 rolls searched ... so finding one in your first box of 50 rolls is good news.
Your 1942-S war silver ... while well worn to AG3/G4 ... is a great find ... I have found only 2 in my entire searching ... my average is one every 134,200 coins ... that's one every 3,355 rolls ... so you did very well on that find.
Hoping you stick with it ... nickel roll searching is great fun and a great way to enjoy the hobby with a real possibility of completing an entire circulation strike set from circulation rolls.
Take a look at my other hobby ... http://www.finewoodcrafter.com
Too many hobbies .... too much work .... not enough time.