If you are currently having 2GB of RAM and perhaps able to buy second expansion module it will be of size of 4GB? It was just my thought (as minimal requirement stays the same: 4GB of RAM for PureOS 10 and for Debian 11).
No if you install the recommended Debian image correctly, the one linked above: Debian 11+non-free. Therefore my popup recommendation here.
EDIT: Your “problem” on related laptop is called “AMD Radeon HD 6770M”, that requires non-free software, as already answered here (and needs to be understood):