This is perhaps the best weekend to try JS8Call. ATM 40m is open for global comms with relatively low power. Almost all JS8Call activity is on the 40 meter band. So if you’re trying it out for the first time, that’s a great place to start.
If a station you can hear doesn’t answer right away, just leave a message on that station. Then call CQ again.
To get an idea of who can hear your station, go ahead and send a heartbeat before you start calling CQ. Other stations around will respond to your heartbeat, giving you some indication of propagation. Do that a couple of times, wait for your responses, then get started calling CQ.
Please remember it’s not FT8. The operator density of JS8 is substantially lower however, this means you’ll have less competition for bandwidth, or being blocked out by those high powered FT8 stations.
Stop procrastinating and give it a try.