Nest or Hive self installation

Been thinking of getting a nest or hive. Had hive in the last place and miss it if I’m honest.

I’m thinking about self installation and watched a dozen YT vids and read up a bit.

Thing is I had a quick look inside my current Honeywell wireless stat receiver and it looks nothing like I’ve seen on YT videos. As you can see there’s a Live jumper to the A terminal.
Any advice or am I best just best paying for installation? Thanks