Good malware sites?
If you are seeking an AV product to install on your iPad, you’re perhaps wasting your effort. There are no Antivirus Products available for iOS/iPadOS. Those that claim to provide AV protection are nothing more than “snake oil” - and should be avoided.
Due to the system architecture of iOS/iPadOS, unless jailbroken (don’t go there!), your iPad is not susceptible to traditional malware infection per-se. However, as with all computer systems, there are still vulnerabilities and exploits to which you remain vulnerable.
Browser-based attacks can largely be mitigated by installing a good, trusted, Content and Ad-blocking product. One of the very best and most respected within the Apple App Store - designed for iPad, iPhone and Mac - is 1Blocker for Safari. Older devices cannot run the most recent version, however, 1Blocker Legacy is available for older iOS devices:
https://apps.apple.com/gb/app/legacy/id1025729002
1Blocker is highly configurable - and crucially does not rely upon an external proxy-service of dubious provenance. All processing takes place on your device - and contrary to expectations, Safari will run faster and more efficiently.
Unwanted content is not simply filtered after download (a technique used by basic/inferior products), but instead undesirable embedded content blocked form download. A further benefit on metered services, such as cellular connections where you data may be capped or chargeable, this not only improves speed but also saves you money.