Yeah, Lego minifigures are pretty small. In the past Lego had made some figures in different sizes, but aside from the brick-built BrickHeadz, they haven't really dabbled in larger sized figures for a while.
If your just starting out I'd recommend you watch these two tutorial playlists. Since you're already a stop-motion animator, a lot of this will be familiar to you. But these do cover some Lego-specifics that would probably be beneficial to you.
Nathan Wells' Bricks in Motion Tutorial Series
& Doug Vandegrift's Brickfilm School.
Larger cameras (like DSLR's) tend to give the greatest image resolution, lens options, and post-production opportunities (shooting RAW helps) however, tiny little webcams have always been heavily utilized in Lego stop-motion for their size - easy to integrate into tiny pre-built sets & spaces - although, obviously, they shoot at a much lower resolution (most can handle 720p or 1080p HD nowadays, though!)
Thanks for reaching out! Looking forward to seeing what you do & come up with! Animating Lego is such a unique and different experience to other forms of animation & stop-motion - but it has a lot of neat pluses as well!
I am available for voice acting & scoring! See details here