The [Youtuber Artifexian](https://www.youtube.com/playlist?list=PLduA6tsl3gygXJbq_iQ_5h2yri4WL6zsS) has some good information on the topic, in which he explores star system and planetry building using equations
(which I am currently compiling into spreadsheets for ease of use).

According to Artifexian's videos, The mass you gave is great (**3.5 Earth Masses** is the absolute maximum size I'd use to make a habitable world), and your moon should be **less than the mass of your planet, but greater than 0.25 earth masses**. This may turn your planet and moon into a binary planet system (like Pluto and Charon) so when calculating things such as orbit you may need to find the Baricentre of the two bodies first.