The licensing information is here: https://www.scirra.com/store/licensing#license2
. A personal license is a good cheap starter option.
Basically, A personal license is just for the named person, but can be installed on any number of machines, as long as the named person is the only one using the machine.
Therefore, as you and your brother want to work on 2 separate machines, then you would both need a license.
If your vision so exceeds your ability, then look to something closer.