Hi heshie1,
If you want to start every from scratch, which I would recommend, just remove every single accessories from the Home app and remove the Home itself (on an iPhone, tap the "..." icon, tap Home Settings, scroll all the way down and tap Remove Home). Also reset every accessory to their factory settings (See their brochure on how to do this as each accessory has its own way to be reset).
With a new Home (I believe one will be recreated for you), just add one single accessory (a smart plug would be the perfect accessory to test but you can choose any other).
Then in the Automation tab of the Home app, create a new automation, choose the "A Time of Day Occurs", select a time of day in the next few minutes, tap Next, select your accessory, tap Next. You will see a gray tile with your accessory (I chose a smart plug here). Tap the tile and move the cursor all the way up so the smart plug is turned on at the time you specified. Tap the check mark (upper right) and wait for the smart plug to be triggered by the automation.
If everything works as expected, start adding more accessories and try to control them with automations.
There are numerous websites you could visit to learn more about home automations. Reddit and YouTube are good places to visit.
Don't hesitate to ask more questions here. My home setup is rather basic (a few smart plugs, a few smart switches and a thermostat relayed by Homebridge) but I'll try to help you as much as I can.
