Johnny, that's a very hard question. Once upon a time, FO s were getting F50 commands very quickly. Too quickly, like 18 months.
What will determine time to command is the number of FOs in front of you and the rate at which commands become required.
The F50s are pretty long in the tooth and will be retired over the next few years. It's also no secret that the ATR will go onto the VAA AoC. What that will mean for commands is anyone's guess.
All you can do is apply and hope for the best.