Accessing/Setting Up Proton Mail Addresses After Purchasing Subscription?

So I’ve recently bought a 2-year subscription with Proton but information about what I’ve bought and how some of it works appears to be sparse, e.g. how do I set up the email addresses included in my subscription? Can I use a mail client application to access the mail or is it only accessible via a browser?

Is it maybe more secure to access it with a browser or a mail client?

Is there some kind of wiki page for how to use all the VPN’s features?

Lastly what does the ‘Secure Core’ button on the VPN control panel do?

It all seems to be working OK at the moment fwiw

Edit: if it means anything I’m using this on a laptop, not a phone but that may change when I buy a new phone

but information about what I’ve bought and how some of it works appears to be sparse

I don’t think so, all your questions can be answered by simply searching for it.

how do I set up the email addresses included in my subscription

If you use a Protonmail domain you don’t have to set up anything, if you use a custom domain have a look at this: https://proton.me/support/custom-domain

Can I use a mail client application to access the mail or is it only accessible via a browser?

You can use both: https://proton.me/support/protonmail-bridge-configure-client

Is it maybe more secure to access it with a browser or a mail client?

Secure in which way? Both options use end-to-end encryption. I would more worry about the device you are using it on, how secure is it. What if you use an outdated browser with many extensions?

Is there some kind of wiki page for how to use all the VPN’s features?

https://protonvpn.com/support/

Lastly what does the ‘Secure Core’ button on the VPN control panel do?

https://protonvpn.com/support/secure-core-vpn/

Thanks for your answers, much appreciated. When I signed up and the payment was processed, I just got the link to dowload the VPN application (which works fine) and that was it, no instructions or anything, I didn’t see any links to anything support-related and wasn’t sure where to look for info so I came here.

As for browsers I only use Firefox, it’s always updated the same day the ‘update available’ alert comes up and the extensions I use (mostly security/privacy-related) auto-update. It’s set up so that the browser cache only uses RAM, but that’s more of a thing to reduce the amount of writes to the SSD.

I spend almost all day & all night in front of this laptop, so it would be a large amount of data needlessly being written to the SSD; I don’t know if it even matters any more with newer SSDs but with the earlier ones limiting the amount of writes helped to increase their service life, supposedly.

I guess my laptop is as secure or not secure as any other Windows 10 machine, I got rid of Cortana & MS Edge and don’t have a Microsoft account fwiw. I removed all the bloatware/free trial crap that was in the laptop when I first bought it. In general I try to keep away from Google. I won’t be adopting Windows 11 so once security updates cease for Win 10 I’ll install a Linux distro and keep Win 10 on a VM.