1. I am developing an event website and my main question is about posting the events. Is it considered public information the name, time and prices of those events posted on the bars, clubs and venue's website?
Answer: Information about the venues where the events are held is not considered personal data as it is not linked to an individual.
2. Can I post those events on my website?
Answer: You can post such events on your website. Privacy Laws including the EU GDPR do not cover non-personal data. However, you may have some other restrictions related to, for example, copyright.
3. Can I use the pictures used to promote the events?
Answer: Pictures are a tad complicated if they can be used to identify people but you could use them though you would need to have a privacy notice explaining where you got the pictures from, for what are you using them, how long you are going to keep them etc. If you want to find out more ab out the EU GDPR, check out this EU GDPR Foundations Course (https://training.advisera.com/se/eu-gdpr-foundations-course//).