I'm in a clinic and there's no Wi-Fi here. Unfortunately, I only have 3GB of data on my mobile phone. What possibilities are there that I also have internet on my laptop? There are so many surf sticks… Can you recommend something? What is useful? I would check e-mails, do some research, make transfers etc., not watch films and Co.
Pay at the hospital and get the Wi-Fi password.
You also need a SIM card with the appropriate data volume for the surf stick.
For the use cases you have described, you can get by with 3 gigabytes of data for some time.
And if I do 2-3 hours every day How long does the volume last?
You can make your smartphone available as a hotspot for your laptop.
If your data volume is not sufficient, you can certainly book more. I can't say whether it is worthwhile in terms of costs or whether it is cheaper to buy a surf stick, sorry.
You can roughly estimate that with a data volume calculator. For example there: http://www.surf-stick.net/datenvolumen-berechnen.html