Hi Daria
$400K is a very popular max price for first time investors and we field many enquiries from people such as yourself, especially in western Sydney right now. The market is very active, with listings down and demand high- it can be tough doing it on your own or with little local knowledge.
Monalisa has given some good ideas for suburbs surrounding Parramatta. Parra itself is fine, but I'd recommend staying clear of the high rises and sticking to the lower entry cost more established walk-up complexes (up to 3 floors) and adding value this way, if renovating is your cup of tea. Look at streets north of the river (quieter, a little nicer and yet still walkable to rail) Harris Park and parts of Granville (there are better streets and complexes than others so do your DD here) and surrounding Wenty, Pendle Hill etc. Not as much stock right now but stay on top of the market weekly, get in touch with local agents and engage in several weeks of physical inspections to develop a feel for what is happening, as well as what's worth buying. Happy hunting