I'm in your same boat. I'm aiming for a HIM in mid September. Starting around now seems pretty reasonable. You'll have to train consistently you should have the time to build up without being "rushed".

I'm using BeginnerTriathletes 20 week HIM plan. I've modified it a little. I've learned that my body just can't do 6 days/week. So I've changed it to 4 days on/ one day off. It adds another 2 weeks to the training time, but I think my body and mind will do better with this.