Automatically buy shares with ETrade stocks

I apologize if this isnt the sub for this but I was wondering something. Is it possible to set up weekly or monthly share purchases through a service like E-Trade? For example I want to be able to take $100 every couple of weeks and purchase however many shares that gets me automatically. I have no problem with just purchasing stocks twice a month like this since I just have a couple Im looking at but it would be convenient as hell to have the process happen automatically.

Yea the auto-buy is a bit of a stretch haha Im looking at a few; OFS, AHGP, SBRA, OHI and PNNT. Admittedly I dont really know what Im doing just yet and Im looking for growth over time. I assume that stocks with decent dividends would be a good place to start but like I said I dont really know what Im doing haha