Lippe-Detmold is a North German minor, bordering Hannover and the western part of Prussia. It is like most of the North German states in Prussia sphere of influence. It produces coal.
Lippe-Detmold can form North German Federation and Germany itself although that is very hard. Lippe-Detmold will be annexed and the game will be over when/if another North German state, most likely Prussia forms NGF. The early parts of the game will center around avoiding this, best achieved by removing one self from Prussias Sphere of influence.
Lippe-Detmold can enact the unique decisions Support The Lippe-Biesterfelds and Support The Schaumburg-Lippes which both give them 5 prestige. There are no difference between them other than flavour. Note that neither can be taken as another nation, so make sure to take it before forming NGF or Germany.
The early game should be all about trying to get away from Prussia. The fact that you actually border Prussia does not make it any easier. But that does not mean, you cannot use them before you do so. Attacking Netherlands or Denmark for an additional state is a good start, since that is required to become a great power.