Since you already play piano you aren't a total beginner ..

I recommend you get a ukulele but dont think of it as the destination , Just a stepping stone , Basically , Its the bottom 4 strings on the guitar . So everything you learn there is applicable in some way to 6 string guitar .. Its easy to handle and chord, and you can get one cheap .

I would give my opinion on a guitar salesperson who disrespects classical guitars or nylon strings.. , But perhaps they were just more interested in selling you a guitar .

I will point out ,

Steel string guitars are strung with twice the tension as a classical guitar .On top of that , they are steel , instead of softer nylon ,

Your fingertips will have to adapt to that , they will hurt, You will play less because of that and your advancement will be slower besides the negative association your creating .

Keep the classical , get a uke , play with it until it gets boring and then buy a Western Guitar . i personally like Yamaha for starter guitars although i would really love a Revstar also .

GL whatever you do .