See a burglar outside, activate a siren remotely?

I currently have no Ring or Alexa. I want to know if I can put a camera to monitor a shed; get an alert on my smartphone when motion is detected; see the shed in real time; and if I want to, manually and remotely set off a siren. I'm lost among Ring, Alexa and Echo... also I'm very old. Hoping someone can tell me what I can buy and how it will work. Thanks!