IPads are famously easy to use and I dare say that you will have picked up most of the basics simply by playing with it, but if you fancy a little light reading then open Safari browser and download the iPad User Guide from the Apple Support website. If you have a specific question or problem just Google it in plain English and you can be reasonably sure of finding the answer in the first few hits.
You need not worry about spyware, malware or hackers getting at your personal information. But the loss or theft of your device is a real concern. Everything stored on the iPad is encrypted but it is only lightly protected by the 4-digit passcode. The first thing to do is go to Settings > General > Passcode, set Simple Passcode to Off, re-enter your original passcode and you will be invited to set a much longer and stronger one.
When that’s done go back to the Passcode Lock page and set Erase Data to on. This automatically deletes your data if more than ten attempts are made to enter an incorrect passcode.
While you are at it go to Require Passcode and change it from immediately to 15 minutes, say. That should keep your personal data fairly safe but you may want to add further layers of protection, especially if you use it when you are out and about.
If so you can install apps that make surfing safer by using a VPN (Virtual Private Network), to encrypt your connection when using potentially unsafe public Wi-FI hotspots, and remotely wipe the memory if your iPad is stolen.