There's no fix and fast rules as to how many cels 
is called a 'decent' cel collection.

Yes, you are right. Two cels is a collection. It 
doesn't really matter on the number of cels you 
collect, as long as you're happy with what you 
have and what you want. Please don't be too 
bothered as to how others would see it or laugh 
at it. And, they probably shouldn't either. 
They're all once newbies to cel collection after 
all.

Take it easy, you're new, you'll be getting a ton 
lots of cels when you start expanding your likes 
on different anime series for cels you might be 
interested in collecting. Your collection by 
then, will grow tremedously without you even 
noticing it. Just like me! ^______^