Upload speed depends on four things. Your iPad's hardware. Your wi-fi router. The bandwidth of your internet provider. The server you are uploading to. I can't offer any specific advice without knowing a lot more about what is going on. Even then I probably can't offer much. It's not an easy thing to solve remotely.
In general:
Older iPads have older wi-fi radios. They are intrinsically slower. The only solution is to get a newer iPad. Even then, you're unlikely to get the same speeds you can from a computer or laptop. Computers have more power and usually better wi-fi radios. Mobile devicescan't transmit at the same power level or on as many channels without seriously draining battery.
Old routers have older radios and modes, and will be slower. More importantly you need to have a good signal with your router. To some extent you can improve this with good positioning and some router settings. In the end, it comes down to a good router. But a better router does you no good if the iPad is too old to take advantage of the newer wi-fi modes. And, of course, a new router won't help with an old iPad.
You're ISP offeres a maximum bandwidth, but you don't always get that. In the end, it may be a matter of paying more for more bandwidth. Also, many (even most) ISP's have slower upload speeds than they do download speeds. There is only so much bandwidth to be had, and one way to get better download speeds is to limit the upload speed. This is the usual configuration for personal accounts, since most people download more than they upload. Some types of ISP and some business accounts are more even. If this is the block all you can do is upgrade or change your account.
There is nothing you can do about the destination server.