Not much detail here as to what isn’t working for you - or what in Safari is causing difficulties.
The first generation iPad Air, an iPad mini2 or mini3 cannot be updated beyond iOS 12.4.8.
Apple released these models of iPad between 2013 and 2014, ending update support for these devices in September 2019. They cannot be updated to iPadOS 13 (or any later major versions of iPadOS) as the internal hardware does not meet the minimum technical requirements for new versions of iOS/iPadOS.
These models of iPad use 7 year old technology. Their performance is constrained by their hardware; they cannot be realistically compared, or expected to perform on a par, with more modern devices that feature much more powerful CPUs and significantly improved hardware.
If you can explain more about the difficulties that you have, contributors may be able to offer some constructive suggestions on how to get the best of the device that you have. That said, given the age of the device, you might be best advised to consider replacement with a more modern device. Even the entry level iPad8 will considerably outperform all older devices - and supports iPadOS14.