TL;DR version: Mail is worth it, VPN depends - but probably not worth it. You do not necessarily need both.
Regarding mail: Mails are for some people sensitive, for others it might not be important at all. If you use mail actively for communication, non-privacy oriented providers which do not provide zero knowledge services are able to “read” your mails whenever they want. Google does that in gmail. It is plausible most other free e-mail services does the same. They do that to gather information about who you are and what your interests are, so they can sell this information for marketing purposes - something Google does extensively through their search engine - the search results you get are tuned to match your interests and companies paying for Ads on the Google search and other Ad platforms they provide. So if a random website sells some spots on their site for ads and connects to the Google Ads platform, advertisement there are also adjusted to match your interests.
Zero-knowledge providers (such as ProtonMail, Tutatnota and CTemplar, to mention the most well known ones) does not have that capability. And this is also why you typically need to pay to get more features in their services. Their income is from users using the service, while with Gmail you “pay” with your mail data.
Zero-knowledge providers does also not have the capability to “read” your mails, even if they want to. PGP based providers (ProtonMail, and CTemplar IIRC) will not have everything encrypted, due to how e-mail data are managed and how PGP works. PGP encrypts the main mail message (aka “body text”) and attachments, while mail headers (mail metadata such as To, From, Subject, etc) are not encrypted. When you read mail from such providers, the decryption happens entirely on your own device and the service provider does not have access to unlock your private key needed.
The challenge with Zero-knowledge providers is that they cannot easily provide direct IMAP/SMTP access without either requiring users to configure PGP locally - or how ProtonMail solves it via the ProtonMail Bridge, where the Bridge application runs locally and gives a local IMAP/SMTP access and the Bridge does all the encryption work behind the scenes on your behalf.
I’ve used both Tutanota and ProtonMail for a while and moved completely over to ProtonMail for my main mail accounts over a year ago. For me, ProtonMail has a very good balance between usability, good user experience and privacy features. Tutanota deploys more encryption to the mail data (they also encrypt the mail metadata), but they do not have any other access to their service than through a web browser or their own apps. There are no Bridge functionality (and it is not planned), and it is harder to import/export mails.
One key thing with mail: I suggest using your own custom domain. “Buy” your own domain and use that via ProtonMail. If you later on decide to move away from ProtonMail, you just swap the mail service on your own but keep all the mail address with the new mail service.
When it comes to VPN: This is a very dirty market segment driven by lots of hype. I would say the vast majority of VPN users may not really need it. Consumer VPN solutions (like ProtonVPN, ExpressVPN, NordVPN, Mulvad, Private Internet Access etc, etc ,etc) does not really give you any privacy nor much enhanced security. These services are more or less a virtual Internet provider, where you shift whom can inspect your Internet traffic from your local ISP connection to the VPN service provider.
Consumer VPNs do have some use cases, like avoiding people on public networks you share with random unknown people to be able to see what you do online. Or to get a more “open” Internet, to avoid certain blocks the local Internet provider imposes (content blocking, port blocking) or to avoid region blocking.
So bottom line is: If you trust the local Internet providers you make use of and are not blocked in what you want to do, there is little value of a consumer VPN service. If you do not trust your internet connections, then a consumer VPN service may make more sense.
But: You need to fully trust the VPN provider of your choice. Because when you use their service, you grant them access to all your Internet traffic.
I personally trust my the Internet service provider where I host one of my public facing servers and the Internet provider I have at home. However, I do not trust various random networks outside my home. So I have set up a VPN server on my public facing server where my computers and mobile devices have a constant connection to when I’m not at home. All my traffic looks like it comes from my VPN server, no matter where in the world I am. So I achieve much of the same as a consumer VPN service could offer, but I decided to rather trust the Internet service provided by my the hosting provider of my server.
With VPN’s it is all about who you trust and who you are willing to pass your Internet traffic through.
Of the consumer VPN service providers I would be willing to trust other than my own VPN setup, ProtonVPN comes high up on the list. But I might also consider the OpenVPN Cloud service (the free plan is fully featured, but limited to 3 simultaneously connected devices), where I would need to provide my own “exit point” for the Internet traffic. The latter one is more initial setup work and requires maintenance of a server running a VPN client only (connecting to OpenVPN Cloud, using one of the three free connections). The former (ProtonVPN) is far more convenient if you want less maintenance.