There are lots of marketing conferences and events (but not all are suitable for juniors). It is definitely worth checking out Barcamps. Last year, they were in Prague, Ostrava, Pilsen, and Kolín. Not only is the admission free, but there are lots of marketing firms and professionals. Ideal for networking!
Regarding paid events, if there’s one I can recommend with a clear conscience, it’s Digisemestr (by Jindra Fáborský). There’s no better event on the Czech market in the price/value ratio. If I were starting a career in marketing from the beginning, that’s where I’d start!
Other industry events:
Marketing Festival
Reshoper
Czech Online Expo
LinkedIn Summit
Newsfeed Day
We can also recommend all specialized conferences from Taste:
Project Restart
SEO Restart
Social Restart
PPC Restart
Brand Restart
Data Restart
Email Restart