I have the gate turned all the way up and I am still getting way to many phantom rhythm notes. Is there any guidance on best practices to prevent this?
Hello Alex, welcome here 
I can not mention all the possible solutions because there is so much information on this subject.
As a newcomer to the forum, start by looking at the posts on this subject by typing keywords in the search box: ghost notes, tracking, etc.
You’ll find a lot of tips on how to improve your playing technique for good tracking.
Do the same for all the questions you can ask about MG and of course, if you do not find satisfactory answers, do not hesitate to ask the question on the forum giving as many details as possible about your equipment (OS and OS version, audio interface, plugins involved and their version, etc).
Here is a random post taken from the search field to start with; it will give you an overview of an efficient guitar playing and a start of explanations to get a good rendering.
MIDI Guitar 2.2.1 & Best instruments and plugins of 2020
Good quest and enjoy MG, it is worth it 