University student. Which is better Air or pro for daily use?

For the usage you describe almost any current iPad would be acceptable. The main differences…

You get fingerprint ID on the Air, and Face ID on the Pro. Both work, but fingerprints tend to be less tolerant of dirty or greasy fingers (pizza and fries?).

Promotion is simply double refresh rate (120 Hz) for the display. That’s nice if you are using a game or video that supports it, but most are still made for the 60 Hz world which you have seen on other screens for many years.

CPU core count? Don't worry about it, you are unlikely to find it is a limitation unless you get into heavy processor intensive work. Your described usage is not going to make any iPad work to the limit.

You have to make a your own decisions, so the suggestion from sberman to try and get a hands on look before you buy is a good idea.

When choosing an iPad, there are many considerations. Perhaps the following will help you to choose...

All current iPad models are capable of running the current iPadOS Operating System - this being iPadOS 17.x

All iPad models have broadly the same core capabilities. Models essentially differ in their ultimate performance and physical attributes. iPad Pro models use FaceID for biometric user-authentication, while others use TouchID. Only iPad Pro models offer ProMotion - this being the higher 120Hz screen refresh rate that provides smoother screen scrolling and motion effects; all other models are limited to 60Hz screen refresh.

You can compare iPad models here:

iPad - Compare Models - Apple

The iPad10 is the current entry-level iPad. The iPads Pro M4 are the opposite end of the scale - top of the range, with cutting edge capabilities and hardware. Between these two extremes is the iPad Air M2, this model offering a mid-range high performance option. The iPad mini6 is perhaps an entirely different proposition - offering a smaller form factor and other differences in hardware and ultimate capability.

All current models of iPad support for one or two models of the Apple Pencil; the Apple Pencil Pro (with additional features) is only compatible with the iPad Pro M4 and Air M2; iPad models with a USB-C port also support the new USB-C Pencil. For handwritten notes and sketches, support for Apple Pencil may be relevant. Ensure that you choose the correct Apple Pencil for your chosen iPad - as they are not interchangeable. Here is the definitive compatibility list:

Apple Pencil compatibility - Apple Support

iPad models that support the Apple Pencil Pro and second generation Apple Pencil are paired and charged using the magnetic charging dock on the edge of the host iPad. This greatly simplifies charging of the Pencil - as the Pencil is kept optimally charged whenever it is not being actively used. Note that the USB-C Pencil does not feature pressure sensitivity.

Also perhaps consider that the iPad Pro M4 models are the only models to use an OLED screen - this being the most power-efficient and offers greatest contrast and brightness of any model iPad - and also includes reference modes for professional colour grading. Also note that the current iPad Pro models with 1TB/2TB storage options have 16GB RAM, whereas the others have "only" 8GB RAM - as does the iPad Air M2.

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 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.

Your question is like asking what model car to purchase.

Use this as a guide. Also consider stopping at an Apple Store and trying both models.

iPad - Compare Models - Apple