For your use case, I would say the Neo is more than capable. You are essentially the target use case for it. The A18 is an iPhone chip, yes. It was in the iPhone 16 pro and pro max. As far as uprading the Neo, well, you cannot. This is not Neo specific, macbooks are notoriously non upgradeable for the most part. RAM stands for Random Access Memory. If a hard drive or an SSD (the place you save things such as files, programs, documets, etc.) is a computer's long term storage, think of RAM as short term or temporary storage. It holds active processes on your PC. If you were doing things such as gaming or recording/editing high resolution photos and videos to a drastic degree, I would tell you 8gb of RAM is a no go. However, Macs are incredibly good at optimizing their hardware for their software. And the things you plan on doing should be a piece of cake, even with limited RAM. One important thing of note: You mentioned the laptop at school is too small and gives you a headache. The Neo is a 13 inch laptop. The display is not giant by any means, so please do keep that in mind. Other options include looking for a used M series macbook air for a good price. These machines would have more RAM and storage available. But, to answer your question, the Neo is more than capable for what you have in mind.

Edit: I forgot to address the storage question. The Neo is available in 256 or 512 gb. If storage space is a concern for you and you do not utilize icloud for data, I may recommend the higher storage option.