I've had the same ph# for many refill of minutes. Just buy a card at a big box store, pay cash for the card. Easy peasy

can use cash to buy the phone and top-up cards. Unless you call or text a lot, you will not run out of minutes.

for 19.95 coin of the realm, a 90 days service card costs the same.  You'll never run out of minutes, if you just hobby with it.  Add minutes through the handset.  The minutes roll over if you don't let lapse.  You can active the phone with no real information & don't link to a web address.

It seems to signal others in your life that you have such a "hobby".

If I let my "service days" expire, you can still refill it and keep the same number for a limited amount of time (30 days maybe?).  Then you lose it.

You can pay cash for the phone and minutes card, go to the library or somewhere and register it anonymously and don't have to give any personal information at all.