I have set my cell phone to mobile hotspot, bluetooth tethering and USB tethering to get internet.
I am close to using up my data because I was downloading some large files.
How can I make it so I can not download any files ?
I did a search and found nothing to help.
By January 1st 2025, I can afford to get internet other ways.
I hope that make sense.
For updates then:
Software&Updates>Updates>Automatically check for updates>Never
For downloading files and programs through your browser all I can tell you is use a little willpower and just don't download anything until you have decent internet service.
I was not talking about updates.
Anything you download including updates will take time and use bandwidth hence you'll use more data. What you do with downloading large files is up to you not a script to keep you from doing it, just stop downloading or go to a local library and use their wifi.
This is a typical case of wanting your cake and eating it, too. EVERYTHING you do via your phone is consuming data: web browsing, email, text messaging, streaming music, podcasts, etc. Not just downloading files. Even system services will consume data. As has been suggested by others, the best way you can reduce your data consumption is through self-regulation. Or by turning off your cellular data capability on your phone. TANSTAAFFL.
I saw nothing but complaining in your reply.
You could set the connection to "metered". In Ubuntu MATE, it's under Network Connections → 
Edit → General. Apps might respect that setting and be more conservative with what they download.
For example, hypothetically, an email client might not sync a folder until manually ran, and images/attachments may not download automatically. If the app doesn't support this, you could manually turn off these settings to spare the bytes.
Turning off images in the web browser can save a lot too.
Depending on your phone, you might be able to set the metered setting for the mobile data too, if you haven't already.
Take a look here if you haven't already but I'm pretty sure you won't like the replies there either.
Stating the truth is not complaining. I have nothing to complain about. You want to tether to your phone but not download. Can't be done.
You have a negative attitude.
I am reminded of an old saying.
"If you do not have anything postive to say, then say nothing."
I can find no Network Connections.
Take it however you want. A lot folks here are trying to help you and you blow them off when you don't like the suggestions,that my friend is the very definition of negativity. When you run out of data the only person you'll have to blame is yourself.
Click on the WiFi icon in your indicator panel and select "Edit Connections" from the drop down list.
This will open the Network Connections dialog. Select the connection you want to meter by clicking on it.
In the bottom left corner of the dialog click on the settings icon (usually a gear). This will open the connection editing dialog as shown in lah7's post. Adjust the Metered connection setting as desired.
