Student or Learner
The no.1 is correct, isn't it? And the no.2 wrong? I don't really understand why.
1. Soon he will start playing.
2. Soon he will start to play.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
There are over 24,000 COCA citations for start to VERB and 56,000 for start VERBing,