what email address are you using? is it a hosted exchange or webmail type? if it's a local calendar, there's not much you can do, you would need to have it in the cloud, or hosted somewhere.
Been looking at this for ages, the only free app that will do it for you is gappssync but then you have to have Gsuite account at $5 a month. A general free or legacy gapps user does not get the outlook sync feature.
I have tried multiple times and end up going back to EM client, mailbird or any other email client that works well with gmail.
I gave up trying and use a Windows Mobile phone. Works perfectly with the three Office 365 Enterprise accounts (mail, contacts, calendars) that I use daily.
Now all systems - desktop, tablets, laptops, phones - are always in sync. No issues.
As others have asked, what accounts are you using in Outlook? If it's an Exchange account, it will sync with Google calendar on an Android phone but you need to set the account up manually and use m.hotmail.com instead of outlook.com as the server.