Hello tali34,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you have questions about using Safari and Google Chrome on iPad. To start, you can use the Zoom feature to enlarge or decrease the size as described here: Zoom in on the iPad screen - Apple Support
To change the amount of time before your iPad's screen goes to sleep, you can go to Settings > Display & Brightness > Auto-Lock to adjust the time.
Yes, Google Chrome is a safe option to use on your iPad to browse the internet.
We hope this helps.
Cheers!