I bought an iPad w/out a sim. Will I ever be able to call or msg.

Even with a cellular model iPad with a SIM you cannot make phone calls or send/receive SMS/MMS text messages. The cellular SIM model iPad is for cellular data (e.g., internet) only.

The only way to do those things on an iPad is if you also have an iPhone; if so you can do those things from the iPad but it uses the phone to transmit. See: Make and receive phone calls on iPad - Apple Support and How to forward SMS/MMS text messages from your iPhone to your iPad, iPod touch or Mac - Apple Support

Without a SIM, no. You'll have to set up cellular service with a provider, who should then supply you with a SIM.