Is Apple Intelligence a separate download or included in iPadOS update?

For devices that support Apple Intelligence - and are in a country where this feature is available - Apple Intelligence will be automatically downloaded to the device when it is updated to iPadOS 18.3.

How to get Apple Intelligence - Apple Support

For iPad, devices with an Apple A17 Pro or M-Series CPU support Apple Intelligence.

Supported languages

Apple Intelligence is available in English (Australia), English (Canada), English (Ireland), English (New Zealand), English (South Africa), English (UK) and English (US) in most regions around the world. In April, a software update will deliver expanded language support, with more coming throughout the year. Chinese, English (India), English (Singapore), French, German, Italian, Japanese, Korean, Portuguese, Spanish, Vietnamese and other languages will be supported.

After getting started with Apple Intelligence, it will continue to work when you travel to other regions around the world.

For European Union residents

Apple Intelligence is available with macOS Sequoia 15.1 or later on supported Mac models. 

For iOS 18.1 and later, and iPadOS 18.1 and later, Apple Intelligence will not currently work if you are in the EU and if your Apple Account Country/Region is also in the EU. If travelling outside of the EU, Apple Intelligence will work on your iPhone or iPad if your language and Siri language are set to a supported language.

In April, many of the core features of Apple Intelligence will start to roll out to iPhone and iPad users in the EU.

For China residents 

Apple Intelligence will not currently work for supported devices purchased in China mainland. For supported devices purchased outside China mainland, Apple Intelligence will not currently work if you are in China mainland and if your Apple Account Country/Region is also in China mainland.

When Apple Intelligence is available in the EU or China mainland, previously purchased devices that support Apple Intelligence will be able to activate and use it in that region.

Your previous post suggests that your iPad is a base-model with only 64GB of internal storage.

You may struggle with an iPad that has so little internal storage. The 32/64GB devices are primarily intended for use in Educational settings, or in environments where the ability to store local data on the device is not required. Together, iPadOS 18.x and Apple Intelligence LLM data requires ~17GB of your available storage, plus additional storage for cached and working data (I typically observe 15-20GB - although this figure fluctuates). Taken as a whole, this is already ~50% of your base storage. Any locally saved files/data will further reduce your available free-space.

It is generally recommended that you maintain at least 4-6GB of free space at all times - as your iPad needs some temporary space to complete many tasks. When performing system software updates, you may temporarily require considerably more.

If considering a replacement iPad, you would be well advised to purchase as much internal storage as your budget might reasonably allow - as internal storage (and other hardware) cannot be changed, upgraded or extended. The available internal storage is fixed for the entire life of the device. If you run out of internal storage for your documents, photos and other data, you will forever struggle and become a source of frustration. It is far better to have more storage than you need, than to need more storage than you have.

A good rule of thumb is to quantify how much data storage you will need - add a healthy margin - then double it. If you are unable to quantify your data storage needs, it becomes more difficult. Whilst I and others cannot make definitive recommendations for your personal needs, objectively I would council against purchase of any iPad with any less than 256GB storage, 512GB and higher having a greater margin for growth.

Within the Apple Support Communities we see regular tales of woe and disappointment when storage requirements are exceeded, necessitating replacement of the device; by contrast, we never see complaint of having too much available storage. It is relatively easy to fill limited internal storage space; perhaps consider higher tiers of storage as providing room for growth as your needs develop or mature - potentially extending the useful usable life of the device. 

Also consider the functional differences between WiFi Only and WiFi+Cellular models of iPad. Aside from the obvious Cellular functionality, only WiFi+Cellular models include GNSS/GPS location capabilities - which may impact any Apps or features that require accurate and consistent location data, such as Mapping. 

Purchase of a WiFi+Cellular model provides access to precise location services, but does not commit you to using Cellular connections. WiFi Only models of iPad have no Cellular or GNSS/GPS functions at all.