So this say “hello, pleasure to meet you.” Someone who doesn’t know Portuguese would think it’s fine though someone who learned a little before hand knows this is unnecessary. Prazer by it self means “Pleasure to meet you” or just Pleasure. I’m starting to see why Duolingo isn’t so good.

Nice catch! Yeah, no one would really say the "em conhecer você" part cause it's already implied by the "prazer" But also no one would actually mind it if you did say it like that