Seeking advice for switching from T-Mobile to Verizon

Hello, I've been a Sprint/TNX/T-Mobile customer for 10+ years and am pretty certain I would like to switch to Verizon for my primary carrier.

I've had long-term TMO reception issues in my neighborhood and work area, and after testing Verizon's towers with a US-Mobile (Warp Network) secondary SIM, the service is much improved.

I had previously stayed with TMO because they offered me some significant credits that lasted 3+ years, which took my monthly bill to $27/month for a single phone line. Those credits recently expired and my bill increased to $72.

I've also been experiencing a recent glitch that disabled my Visual Voicemail entirely (separate post), and T-Force has not been able to assist after trying the basic troubleshooting steps.

I was hoping this sub could provide general advice for the switch from the T-Mobile side. Not sure if there are any steps I should take to ensure a smooth transition and retain my current phone number.

I have a paid-off Galaxy S21 Ultra phone that suits my current needs and I'm happy with, but would maybe consider a new device if there are any recommended promos for switching to Verizon.

Really appreciate any advice or input. Thanks in advance for any help.