A lawyer is a general term- in the UK, we have solicitors (general lawyers) and barristers (specialists)- both are lawyers. In the States, attorney is used.
A gerund is the -ing form when acting as a noun:
Smoking is bad for you. (Smoking = subject of the verb 'is')
A present participle is the -ing form when part of a main verb or an adjective:
It's an interesting idea. (adjective)
I was working all night. (main verb)