The easiest answer when it comes to outdoors is if you have a product or service that is meant to be outside, then you should film outside. The main benefit of filming indoors is that you can control the environment and keep the videos consistent from one video to the next.
Whatever you decide to do, just be aware of things such as lighting, audio quality and having clean, non-distracting background. Just making videos to market your business is a big step, so just play with what works best when filming and you'll eventually find your sweet spot.
Let me know if you have any questions about producing marketing videos, or get in touch about getting help with your videos.