I checked your logs and haven't find any problems. But you said that there is
No firewall on the server. It could cause problems, because you should enable forwarding for working NAT. Here is output from guide.
In order to configure your ufw settings for VPN traffic first add the
following to /etc/default/ufw:
Now change /etc/ufw/before.rules, and add the following code after the
header and before the "*filter" line. Do not forget to change the
IP/subnet mask to match the one in /etc/openvpn/server/server.conf.
The adapter ID in the example is generically called eth0 so edit it
for your system accordingly.
# NAT (Network Address Translation) table rules
:POSTROUTING ACCEPT [0:0]
# Allow traffic from clients to eth0
-A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE
# do not delete the "COMMIT" line or the NAT table rules above will not be processed
Open OpenVPN port 1194:
# ufw allow 1194
Lastly, reload UFW:
# ufw reload
In order to allow VPN traffic through your iptables firewall of your
server, first create an iptables rule for NAT forwarding  on the
server, assuming the interface you want to forward to is named eth0:
iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE
And don't forget to enable forwarding in sysctl
sysctl -w net.ipv4.ip_forward=1