If you start an LLC, you're going to be applying for an EIN anyway. You'll definitely need an accountant. Probably could find lots of templates and documents online for free (lawdepot.com, pandadoc.com, eforms.com, docracy.com, usefyi.com) And yes your crew would probably be 1099. Source: almost 3 years ago

With the assistance of its parent company Meta, Instagram has just recently launched the beta of its AR ads through its Spark AR Platforms. This interactive ad layout allows users to interact with their ads whether it's trying on clothes or testing out furniture for a new home. Meta insists that these engaging ads will allow brands to “prepare for the metaverse,” as many are anticipating and developing technology... Source: over 1 year ago

I remember seeing this Corridor Crew video and they used something called Spark AR to do real-time face filters. Source: about 2 years ago

Like u/Nexen4 says, create the character in a modelling package, then import that into SparkAR to make a filter. Source: over 2 years ago

I haven't really used any. Though a friend of mine was playing with Spark AR Studio from Facebook. Source: over 2 years ago