anastasia1, maybe you should tell people about it, but not make it a big deal that they should come. after all, it is not like a graduation or retirement. having a party is totally optional.
if you tell some people and not others, the others may later get offended, so try not to offend anyone. if you tell them and then say, 'you can come if you want', then, if they don't want to come, it is easy for them to decline. then you can invite a close friend, without feeling like you have to keep anything secret (secrets always get out; best not to bother with them).
i was the only one in my family who felt positive towards orthodoxy and my protestant friends were not encouraging me either. in the end, the closest person to me was not interested in coming, so i didn't invite anyone else.
also, there were only 2 days between agreeing a date with the priest and the date coming, so there was only my priest and i there, plus another church friend who was busy setting up the church ready for raising of incense and who was involved a little. no one else had arrived yet.
but all the church people (of whom i knew about 90%, it was a smallish church) realised it had happened as, afterwards, i went up for Holy Communion for the first time, so everybody congratulated me afterwards during coffee. that was really nice, but i couldn't stay around as i had to rush home and cook dinner for guests! so you don't have to do it in a rush like i did, but i had been an inquirer for 3 years by then and was in a rush to do the deed, once i had established that it doing it would not cause too much trouble at home.
i think my friends were a bit like dominika's friends. they knew i had been going to 'that funny church' for some time, so it was not a big deal to them at all. when i told them afterwards, it was like, 'oh, o.k. but make sure you a still a Christian and you still read the Bible and pray' (like as if i was getting into a weird cult!)