Riveting

Even though you're just getting into it, and have only a little knowledge, you made a smart choice in getting a power meter (PM). PM's are a great tool, and you don't have to get all fancy to use it. Just look at the power you're putting out while you're riding for a certain duration, and make small incremental improvements (like 5-10watts more) in your power output for that duration, every week or two, or whatever works for you. And do this for lots of different durations, like 10 seconds, 30 seconds, as well as 1, 5, 10, 30 and 60 minutes. And just try to hold a steady and maximum power that you can sustain for each those durations. A lot like going to the gym and incrementally increasing the weights you're using, depending on the number of reps your doing for that set. I've had a PowerTap G3 hub PM for the last 7 years, and used it to build up to 1,000 watt sprints for a few seconds, as well as 233 watts for an hour (aka your FTP60), and I'm sad when I have to ride one of my other bikes that doesn't have a PM. Just review your power curve and look at what you've done in the recent past, and make small improvements, week after week, month after month, year after year.

But IMHO, forget about phone apps (for various reasons like connectivity issues to the PM, phone battery life, phone screen visibility in the sun, and the phone screen getting broken easily even in a minor fall, or if the bike falls over while just leaning on something) and just get an entry level Garmin bike computer, like the model 520 with grayscale screen and no touchscreen, that's what I have. It's pretty small and durable, and the battery for the first few years lasts a long time (10-15 hours as I recall), much longer than your phone ever will with the display on bright). The 520 will effortlessly connect to the PM via Bluetooth, do all the ride recording, GPS navigation (if that's something you need), and show the live power meter data on screen (I like to show the 3 second avg.), and then when the ride is done and you just hit save, and it'll effortlessly, and in the background, upload all the ride data (via your phone's Blutetooth) and then send it to Strava (once you set that up) where you can quickly analyze the data and your power curve, or you can also send the data to GoldenCheetah and do more serious analysis, if that's your thing, but it's not entirely necessary. the Garmin bike computer will also connect to a Bluetooth Heart Rate Monitor (HRM) chest strap if you happen to care about your heart rate, which I would recommend to a newbie trying to baseline their new cycling fitness for the first year.