Welcome to the forums - and well done on getting your first smartphone
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I've not used the Doro 8030 before, so I don't know much about this model - but it runs an operating called Android, which is very popular (and on the phone I use at the moment).
You can connect and disconnect to the internet as you'd like, you'd need to disable "WiFi" and "Mobile Data" to do this (and then enable them when you want to use it again). To do this, swipe down with your finger from the top of the screen to bring up the status bar, then use the quick settings button to disable the two features I mentioned. The manual has more detailed instructions on how to do exactly this on page 12 and 13 - here's a direct link:
https://www.hearingdirect.com/media/wysiwyg/Doro_8030_User_Guide.pdf
However.... I wouldn't actually recommend that you do this
. If you want to disable the internet so that it does't beep or make noises, it may actually be better to just put the phone in to "silent" mode instead. It's quicker to do and means that you can still use your phone for other things without it making any noise.
I'm not sure how to enable silent mode on your phone, but I think it will also be a quick button on the status bar menu I mentioned above. One click and your phone will stay nice and quiet
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