I have gotten a MacBook for my high school, and as I have no phone or other portable mobile devices, it makes it really complicated to contact my parents, when they don't have apple phones, and especially when the only way I know is email. Help and suggestions would be gratefully accepted.
You could use an SMS Gateway to text your parents from an email address.
For example, if your parents are in the US and have AT&T cell service, you could send an email to
firstname.lastname@example.org. The person with phone number (555) 555-1234 will get a text with the sender, body, and subject of your email.
Note that this will not work from your school email if your school blocks emails from students to outside addresses.
One possibility is using SMS. In some places you have free, web-based SMS services that will allow you to text any phone in the country for free. In other places you have to pay a small amount to be able to do so.
Another is using third party apps such as Skype, WhatsApp or Signal.
Your family could do far worse than choosing signal to message each other.
Mac, Windows, Linux, Android and iOS all have official apps and support.