Hey @Photovongsa 
Welcome!!!
What you are doing sounds just fine. Outside riding is a bit more messy than indoors, so using those 5 miles to the veloway as your warm-up is great. Starting the ride from home and extending the warm up until you get to destination.
As far as the AI FTP Prediction goes, we’ve identified an issue with how our model projects planned outside workouts. If the entire plan is set up as outside workouts, this affects your predictions more than most.
Our team has a fix ready for this that will go out alongside some broader model improvements, so predictions for outdoor plans should be more accurate from the start going forward.
That said, your prediction is still going up! And it looks like your rating your interval workouts as Hard-Moderate + you’ve definitely noticed increases in speed + endurance!