Make sure your shoulders and upper arms are covered, nothing transparent or too clingy, skirt to the knee at least etc. There are those who dress daringly, I would look at them strangely in my home country (especially those who should be stopped by the spandex police - which exist only in my imagination - for "gross" violations)

Ramadan will be ongoing in August so you can't eat or drink in public between sunrise and sunset (unless you're a loutish inconsiderate idiot who doesn't mind running the risk of a 3 month jail term and there are some about - moreso here than even the Emirates)

Get used to being stared at. It's a cultural thing (but not necessarily Qatari - mostly Asian) by men who have left literally everything at home and are working here to try and provide for their immediate and extended families. Mostly harmless, but can be unnerving to the unitiated.

Hope that helps