How can I locate / activate Send / Receive tabs and functionality?
You need to have a Shelly wallet not Byron and you also need to be fully synced in both chain and wallet. If you only have a Byron wallet you need to convert it to a Shelly wallet. There will be a regular transaction fee to send the funds from the Byron to Shelly wallet.
Lols! They are probably still working on the page or the url changed something. Basically just click the create Shelly wallet and follow any prompts. It takes care of everything for you. Shelly wallet is just the new style wallet needed for staking. Byron is the old style wallet used pre staking and is not compatible with the new network. This is why you need to create the new Shelly wallet and convert your funds over. It’s a bit more complex and elaborate than that but that’s the easiest way I can think of explaining it.
OK, thanks for that, I’ll give it a shot