Absolute newbie looking for some advice on where to start (UK)

Hello all,

I’m a new starter with HA, looking to figure out how best to build up my knowledge and gradually migrate my home automation setup from SmartThings to HA. So far I have installed HASSIO on an RPi 4 and that’s as far as I’ve gotten. My existing home automation setup is as follows:

Hubs: SmartThings, Hue, Blink, Hive

Devices: several Xiaomi door and window sensors, 1 Xiaomi motion sensor, 1 samsung motion sensor, 3 Blink cameras, 1 Canary camera, 1 revolink camera, 4 Sonos speakers, 1 Logitech harmony hub, several Hue/Hue-compatible bulbs, 2 Xiaomi smoke detectors, 1 Nest smoke detector, 1 Samsung smart plug, 2 Aetotec nano dimmers & one Hive thermostat

Automation: Some basic security automation that triggers the SmartThings routines when I leave the house based on phone geofencing. Door & motion sensors and Blink cameras are armed by ST and I have an IFTTT trigger that arms the Canary camera. This then arms the ST security.
Everything else is done through the respective dedicated apps.

Objectives: As far as possible end up with a ‘single pane of glass’ for all home automation, rather than the multiple apps I use now. Improve the quality and functionality of my home security config (ST geofencing is slow, ST doesnt give me much in the way of response options other than ‘set off the alarm if a sensor triggers’). Do away with multiple separate hubs where possible. Reduce dependence on the cloud for processing.

Of course there is lots of guidance on how to work with all these devices in the forums, however I’m hoping people can help me identify a logical path to migrate my particular setup so that I can get a feel for the capabilities of HA and invest in the additional h/w over time (e.g. zwave adapters) rather than me just jumping in at the deep end by accident and having that much harder a time getting my head around the whole thing. I’m also mindful that some guidance differs for the UK (where I am based) where things work on different frequencies and certain h/w is harder to get hold of compared to the US. From a skills perspective, I have been fine implementing custom device handlers for some of the devices I own to get them working with ST, and am comfortable with basic scripting tasks.

Any and all advice will be most appreciated!