Open Minecraft, and make sure that you are logged into your Microsoft/XBOX account.

Select Play

Select Servers

Select Add Server

In Server Name enter a nice name like LGMC, or London Gaymers

In Server Address use play.mc.londongaymers.co.uk

Leave the Port as default 19132

Select Save

Now you find the server you added on your Server tab.

Select it

And then select Join Server

You won't need to add the server every time, as it'll be saved, and you can just skip to this step.