VesperArcade has created this video, which goes into details about KOFXIV’s net code, what starting characters a newcomer can pick and also the early tier lists for the game.
In fighting games, characters have varying barriers of execution. Some can be incredibly easy to pick up and get going with, while with others, you’re going to have to exercise some patience and try to understand what the character’s about.
Antinomy brings up a useful guide for the players to start up with their characters, as he's provided the graphic below. Based on the graphic below he classifies them into 3 different categories which vary from easy (Green) being characters that will force you to focus on the basics of the game, Medium (Yellow) similar to Green but more gimmicky and Hard (Red) consisting of unorthodox characters that need only be looked at once you have the basics of the game down.
"KOF Guide Chart"
You can also take a look at top KOF player, Xiaohai’s early KOF XIV tier list below. It seems that Athena and Nakoruru are the cream of the crop, with team villains sitting right at the bottom of the tier list.
Xioahai's The King of Fighters 14 Tier List
"The King of Fighters XIV Good Starting Characters to Learn/ Tier List"