In all honesty, as a new player I never worried so much about what the name of a champion was.... i was more preoccupied in figuring out what they do. You do not need to know the name if you play the champion once or twice and read the skills (highly recommended to do this with ALL the free rotation champions in a bot game so you can learn more about them as a new player).... but the primary source of how you will be picking your champion and figuring out who to ban, will be by the portrait. So it would be best to learn the portraits more since that will be how they look on the minimap, in the ally team bar, in the death of enemy bar, for special bars for champions like Neeko, Kindred, Rengar... could be others but thats the main 3 i can think of.
As a new player, you do not have the knowledge per se for figuring out what champion is physical or magic damage... which builds tanky... if you need cc.... or anything of the sort.
The only time you will be refering to the name of the champion is at times like this in chat, or with the domination tree in the bottom row there is 4 runes that when hovered over in game will list the name of the enemies you have or have not killed yet. If you need to know the name of the enemies in game.... press and hold tab.