The iPad2, iPad3 and iPad mini1 can only be updated to iOS 9.3.5 (WiFi Only models) or iOS 9.3.6 (WiFi & Cellular models).
Apple ended update support for these models in September 2016. These models of iPad cannot be updated to iOS 10 or later major versions of iOS, as the internal hardware does not meet the minimum technical requirements for new versions of iOS/iPadOS. This limitation cannot be bypassed; these are 32-bit architecture devices, whilst all recent versions of iOS/iPadOS are designed for 64-bit hardware platforms. iPad2, iPad3 and iPad mini1 are obsolete.
You may need to consider that compatible Apps for older models of iPad are increasingly difficult to find - as App Developers have dropped all support for 32-bit devices.
As older versions of Apps are removed from the Apple App Store, you’ll not be able to (re)download or install them - which may severely limit the usefulness and utility of your iPad. As such, if you want or need to access current Apps requiring more recent versions of iOS than your iPad is capable - such as the YouTube App that requires iPadOS 15 or later - you have no alternative other than to replace your iPad with a much newer or current model.
Of current models, even the entry-level iPad10 has specifications and capabilities that will massively outperform you current iPad - and supports the most recent version of iPadOS, this being iPadOS 17.6.1.