ok, base on your output the forticlient vpn configuration should look something like this :
where the Pre-shared key is what you have configured and if you have a peer id configured you should put it in the Local ID field.
afterwards, you should have firewall rules from the source interface Access-Distant and source address object range 172.16.10.10-172.16.10.20 to whatever destination interface and destination object you need.
L.E. in order to try and debug the issue that you have, you should look at https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-IPsec-VPN-tunnels/ta-p/195955 and start the debug, then initiate a connection.
