Setting up my LG x Venture to work with Outlook 365 in the cloud

I have a wireless plan that both my husband and I are on, I tried to use the LG email app (my old phone was Samsung and Samsung's email app, contact app and phone numbers all synced with Outlook 365) but the LG email app would not sync with Outlook 365. I then down loaded the Outlook 365 app and was using that but during one of the upgrades, it quit working. so I went back to my original question and found that James had said to go through the AT&T trouble and resolve tool. I went through the steps until it said log onto your internet mail provided and send yourself a message,. Since I never open a web browser and sign in to office.com. Why should I since it is set up on my computer to sync, I got stuck at that step. Having never log on using the web, I do not even know where to begin. probably do not remember my web password since it was set up on this computer so many years ago.