You probably have xtra options here. I would maybe consider Bd6+Ne7+Bf5 type of setup - of course depending on what white does.
For the typical plans I recommend consulting a book, an educational video or whatever. This is really too vast topic to explain in a forum post.
What are blacks and whites plans in the QGD exchange?, also if i havnt played nf6 yet, do i have extra options? :
so, the position i reach looks a bit different than your average QGD ex. since nf6 is ommitted and I have c6 instead.