One of the best things that you can do to keep your online accounts safe is to use two-factor authentication. In fact, my school district just made all staff start using two-factor authentication on their G Suite accounts. Here's how you can enable two-factor authentication on your Google account.
The mandate for all staff in my district to use two-factor authentication was a response to a few faculty members falling for phishing scams that compromised their G Suite accounts. Here's a Common Craft video that explains how common phishing scams work.
Of course, the first line of defense in protecting your online accounts against brute-force attacks is using a strong password. Here's Common Craft's explanation of how to create a strong password.
Disclosure: I have an in-kind relationship with Common Craft.
