Yes, only way to not get calls or texts would be to turn off cellular phone side, which would turn off data and defeat the purpose.

If you have the phone on, I usually forward my number to a google voice number, so the actual CALLS don't hit the phone/voicemail and you don't get charged incoming call and incoming voicemail (you get charged for both for each call that comes in and goes to voicemail).

As for texts, I believe that incoming texts go against whatever plan you have. so, if you have say 200 texts, they would come from that. Or, if you have unlimited texts, then the INCOMING ones comes from that bucket. OUTGOING texts are .50$ a text or you can buy a bucket of outgoing texts for 10$ for 50, making them .20$ a text..but overages are a bit higher.

then, the data plan you buy would just go against what you use. I turn off a LOT of settings when I travel abroad. email on manual, show just the header. Don't download attachments unless I click on it, that sort of thing.

With some good management, you can get by with 120MB for a week. Using wifi when available and making less than 20-30 min of calls on the cellular side.