My first ipad

Given your stated needs, the current entry-level iPad9 will likely meet you immediate needs. You can compare all iPad models here:

iPad - Compare Models - Apple

Whichever iPad model you choose, 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 cannot make definitive recommendations for your personal needs, objectively I would council against purchase of any iPad with any less than 256GB storage.

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. 

Consider also the functional differences between WiFi Only and WiFi+Cellular models of iPad. Only WiFi+Cellular models include GPS capabilities - which may impact any Apps or features that require accurate and consistent location data, such as Mapping. Purchase of a WiFi+Cellular model does not commit you to using Cellular connections, but provides this flexibility should it be needed.  WiFi Only models of iPad have no Cellular or GPS functions at all.

I would purchase a newer one, but you don’t need an iPad Pro for that. I have an iPad 6 that handles the above quite well (I don’t play exciting games but it still handles them), so an ipad 10 should do it for you.

you also want to purchase as large of a device as your budget allows since the memory is not expandable.

you may also find a Mini 6 could also work if you don’t mine the smaller screen.

If you also factor in a keyboard/keyboard case your will find that your ipad is pretty much a mini laptop. (Just with no real ability for plugin accessories)

You might find 64GB sufficient, but as you use the iPad, you’ll likely find that you use it for activities than you initially anticipate. With a 64GB device, it is really, really easy to exceed the available storage.

Your usable storage is considerably less than the overall storage might suggest…

The iPadOS16 Operating System alone requires ~10GB storage. To this, expect the OS to routinely utilise a further 10-15GB for temporary/cached storage. For practical purposes, you should anticipate having little more than 40GB of usable file storage.

While you need sufficient free-space to download and unpack the system software update - and have adequate additional working space with which to perform the update process - the installation package itself is deleted upon successful installation.

The amount of space occupied by the installed Operating System will change - and may occupy some additional space upon completion of the update process. Equally, it is possible (although perhaps unusual) for the updated OS to occupy less internal storage.

Point-updates are typically quite small - whereas update from one major version to another (such as updating from iPadOS15.x to iPadOS16.x) will require considerably more available space to download and install a complete new OS.

I hope this clarification is useful.