If you filing date is around or before the service

center processing time, you can expect to hear something within a couple months.
In case an interview, CIS first transfers your case to a local office, after a few months, local CIS office sends you a notice for interivew about two months in advance. Do not worry about it.

However, CIS may issue you RFE, so you need get your mail taken care of well. In case a RFE, you need to come back quick to reply the RFE promptly.

And you also need to get an AP, in case an approval when you are out, you can come back on AP.