The iPad5 fundamentally does not support Apple Pencil - as it lacks the specific screen hardware with which the Apple Pencil interacts with the iPad screen. For information, here is Apple’s definitive compatibility list for Apple Pencil and iPad:
Apple Pencil compatibility - Apple Support
There are third-party Bluetooth Stylus’ available which offer limited support for iPad - perhaps the better known being those manufactured by Adonit:
https://www.adonit.net/
Bluetooth Stylus’ are fully reliant upon support being explicitly provided by third-party Apps - and if only for this reason, support is very limited - as will be the usefulness of a Bluetooth Stylus.
The remaining alternative is a Capacitive Stylus. Be aware that a basic capacitive stylus offers no more capability or function than a fingertip - although for fine-tipped examples may offer slightly greater precision.
If you have need for an Apple Pencil, you’ll need to consider replacement of your iPad5 with a much newer model. Of current models, even the entry-level iPad9 has specifications and capabilities that will massively outperform you current iPad - it supports Apple Pencil, is compatible with iPadOS 17.x and current Apps. Other models are more powerful still.