You need a WHEN to trigger the flow so there will always be one, and only one, WHEN.
In this case the WHEN is the time, that's the main driver here, ie 'I want my lights to turn on at 8:30am.'
Then you can have as many ONLY IFs as needed, so:
I want my lights to turn on at 8:30am.
but ONLY IF I am in the house (location thing) and ONLY IF it is a Tuesday, (Date / Time Thing) and ONLY IF Variable 'Bob' is set to true, (Variable Thing) etc etc etc etc
Then please run the flowing flow, turn on lights, run timer for 1 hour and then turn off my lights
Only when all the initial conditions are met will the rest of the flow run. Have a play around creating flows and take a look at the cheat sheet for condition joining and it should become clear.