Awesome! That's exactly how I got started. I did some Pre-Sales volunteer work. It helped that I had some industry experience but it's a great strategy nonetheless. The job market appears to be pretty hot right now for Anaplan Modelers so you may be able to get a paying job without having to volunteer.
If you haven't already, go ahead and get the Anaplan Way certification so you can get the certified modeler certification.
Subscribe and Follow Anaplan and also follow the hashtag #Anaplan on LinkedIn.
Make sure to show your L1/L2 certification on your LinkedIn profile and also make sure the words "Anaplan", "Modeler", and "Level 1 Modeling Certification" and "Level 2 Modeling Certification" are somewhere in your profile. This will help recruiters find you.
Something I did my first year was I "interned" (read: volunteered) for a consulting firm to get experience. That may not be practical for you but it's another way to get started.
Lastly, work towards the certified modeler certification. That's the inflection point where most recruiters and hiring managers gain confidence in your ability to model real business use cases. You got this!!