Are there any decent open source alternatives or should I be looking to go down the building route?
I am a coding newbie so would be a bit daunting!
Node-Red is probably your best bet
it’s functional with a lot of plugins available as well as relatively easy due to the “flow” workflow
one other command mentioned Home Assistant but even among the Home Assistant community there are quite some people using Node-Red together with Home Assistant to achieve their goals
I’m actually migrating away from Node-Red in HomeAssistant.
Don’t get me wrong i love Node Red, but HomeAssistant’s automations are now capable enough to do about 90% of what I need around the house.
Now, if you’re automating like a large growroom and you have hundreds of lights and sprinkler valves to automate against temp and soil sensors…
if your goal is to automate your home (or lab, or work place) I also would highly recommend Home Assistant but I hesitated to recommend it anyone since OP didn’t really explained what they actually want to with it
i.e. if your goal is automate rss feeds and notifications than Home Assistant ist just completely overkill for this task
I would start with home assistants built in automations and scripts before diving into node-red. Node-red is great for complex automations, but if all you’re doing is turning on lights and stuff, just using HA is more than enough, and has a much easier learning curve, IMO.