Thanks for the shout, but a lot of my posts are extremely technical and would only be confusing to someone in this situation.
the following is a good “getting started with Echo” guide for the UK that is specific to home automation.
Beyond that…
BUDGET
Budget makes a big difference. Hue devices are great, and I highly recommend them (with their Bridge) if you can afford them. But if you can’t, the Ikea Tradfri line is an excellent low cost alternative, and will work either with its own hub or with the Hue bridge. So have a sense going in whether you want top of the line or basic functions at an economical price and let others know when you ask for advice.
https://www.ikea.com/gb/en/cat/smart-lighting-36812/
https://www2.meethue.com/en-gb
Are you automating for fun or for practical reasons?
Be honest with yourself. Home automation is a great hobby, and enthusiasts stay up with the latest features, pour over “coming soon” announcements, and buy a new gadget before they’ve decided exactly What to do with it. 
problem-solvers have a specific problem they want to solve, like letting in the dogwalker, and suspect home automation would be the easiest way to do that.
See the following recent discussion.
Suggestions to make existing system more effective? (UK)
AS FOR HUBS…
Enthusiasts will tell you you should definitely get one. Problem-solvers will tell you they may be more trouble than they’re worth. 
These days there’s a lot of stuff you can do without a hub, particularly with Echo, so it comes down to both budget and your interest in exploring the edges of new automation. But save that decision for a bit and first just explore what you can do with the echo as your base.
(If you happen to use Apple devices, you can also start with HomeKit, an excellent basic system built into iOS. These days many smart home devices work with both Echo and HomeKit.)
If you have the budget, I also personally recommend the Hue bridge for a phase one system, which works well with almost all of the other systems out there and gives you lots of possibilities. But that’s up to you.
(One last thought…if you are looking at thermostats, I personally prefer Ecobee to Nest. Nest tends to get all the publicity because it was first in the category and has a great marketing team, but ecobee actually works with more systems and has some very nice features.
JMO, of course.)