1. Stay at 1mg. Same molecule, same dose. No reason to change unless you're titrating up anyway.
2. The salt form question is actually important and often misunderstood. Semaglutide sodium (acetate) has a different molecular weight than semaglutide base. If a pharmacy labels their vial as "5mg semaglutide sodium," the actual active semaglutide content is slightly different due to the sodium counterion.
In practice, reputable pharmacies account for this in their formulation so that the labeled dose reflects active peptide content. But it's worth asking your pharmacy whether their stated dose is based on the base or salt form. This is one of those details that separates a good pharmacy from a mediocre one.