use 2 pole circuit breaker for both basement light and plug
Depends what you mean by "2-pole".  There's real 2-pole breakers, and then there's double-stuffs (twin, duplex, tandem).  Not the same at all. 

It's always OK to run 2 simple circuits -- i.e. each circuit has its own cable and the cable contains its own dedicated neutral.  

However, if the 2 circuits are in 1 cable and share the neutral, it must be a 2-pole - a double-stuff will overload the neutral and potentially shock installers. 

If the breaker is a true 2-pole, then they will common trip, meaning if one overloads it will trip the other.  There's nothing wrong with that, but it might be a nuisance. 

If the 2 circuits do share the neutral, that is called a multi-wire branch circuit.  Common trip isn't required, but common maintenance shutoff is... and a 2-pole breaker does provide that.  In fact, that's what we recommend for this type of circuit, because a 2-pole breaker is the easiest way to do it!   Further, this is the only way to do GFCI on this type of circuit.