it down and stand up when other people do. Look forward and pay attention, if you aren't interested pretend to be. Don't worry about not knowing the responses, if they aren't written down in the program. You can look them up online if you want to know what to expect; google "order of mass".
I didn't look at this close, but here's one:
it looks pretty accurate. There may be some differences.
When everyone kneels, don't sit there like a dummy. It's really offensive. Kneel with everyone else, cup your hands as if you are praying, and pay attention up front. Don't look around. Because the bread and wine are being blessed, everyone is kneeling because they are quite literally kneeling in the presence of Jesus.
People who aren't baptized and confirmed Catholic are not allowed to receive the Eucharist (the bread or the wine). However, her parents would respect it if you stood up, filed out with them, walked up to the preist and put your arms crossed over your chest (arms crossed, hands up by your shoulders), bowed your head and received a blessing from the priest. It's not looked down upon to simply receive a blessing, you will see other Catholics likely do it. In some places though, it is frowned upon to just sit there, so I would recommend you play it safe and go up. LIke I said, her parents will appreciate it a lot.
Lastly, don't tell them you learned this from NS. Tell them you "researched it online". Makes you sound like you are a conscious man that wanted to be respectful of their beliefs = Brownie points for sure.