Any files that you store in iCloud will be accessible to your iPad, iPhone and Mac - regardless of where you are on the planet. You will simply require an internet connection to access any data stored in iCloud.
Any files stored locally on to your Mac computer's local storage will not be remotely accessible. Remote access to local files will require your Mac to be powered-on/running, with a network connection, and be appropriately configured to share specific files or folders. If you are away from home, this is unlikely to viable for many reasons - including but not limited to safety of leaving a computer running and connected to AC Power for extended periods while unattended.
You mention that you are considering an iPad Pro 9.7". Be aware that this model is the first generation (obsolete) iPad Pro - for which you may encounter difficulties finding Apps that remain compatible. If purchasing a new iPad, you would be best advised to consider a much newer or current model iPad - of which even the current entry-level iPad 10 will offer superior capabilities and performance.
If physical size is a major factor in choosing an iPad, consider that the current 11" models of iPad Air M2 and iPad Pro M4 are very similar in size to the first generation iPad Pro 9.7".
You can compare the size and specifications of all models of iPad here:
https://www.apple.com/uk/ipad/compare/?modelList=ipad-pro-11-m4,ipad-air-11-m2,ipad-pro-9-7
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 - 512GB or greater offer a greater margin as your needs develop.
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.
