Ganttproject won't open - is there a problem with Java software?

Hi,
I have Mac OS Mojave and last night downloaded your Ganttproject and Java 8 Update 201 software for Mac.
I can see I have downloaded both (they appear on my desktop and Ganttproject appears in my Apps) but neither goes beyond the first icon screen when I double click and I cannot find the Java software in my Apps.
I’m not computer savvy but I thought I’d followed the right steps.
Please help so I can start gantt charting.
Thanks,

Please try workarounds from the Knowledge Base article on Mojave

Thanks Dmitry but I can’t even find ‘terminal’ to search for ‘java-version’. I need someone to call me and talk me through it. Are you available at 6pm today Canberra time (AES)?

Best regards,

Babcia

Type “Terminal” in Spotlight.