Just as some others have said, I suggest Stessa as a person starting out. I have about 5 rentals now with a partnership in an LLC. I just created another "Portfolio" in Stessa and associated costs directly toward the portfoli. This allows me to keep money streams separate and tidey. With Stessa PRO, it can do Schedule E and a number of other very useful reports. I would say that it has its wierdness, don't get me wrong, but with enough playing with it, its very useful for a low cost. You got to play with the transactions, but what I do like is that it doesn't let me create categories. I say this because I like it standardized and aligned with what my CPA is looking for. Its not super fancy, but it gets the job done.
Perhaps one day I'll need to migrate over to QB, but not until the time invested is worth the return. Right now with a small portfolio, I don't see the need for QB, but I'm sure there will become a turning point as now I just closed on the first BRRRR with my LLC.