You SSH in and install both.

Yes,you can do.
if you have one ubuntu droplet.
so,you can starting from wordpress.

install wordpress need:
apache/nginx+mysql+php-fpm php-xml php-mbstring php-imap php-mail php-memcache

1.install command(if you want install apache,so you can apache replace nginx):
apt-get install -y nginx mysql-server mysql-client php-fpm php-xml php-mbstring php-imap php-mail php-memcache

2.after,mysql need you setting one password.

3.go install finish

4.please you in browser visit you droplet ip,watch nginx or apache is really working.

5.open page path. (cd /var/www/html) in here use wget download wordpress (download address you can on wordpress website get)

6.unzip

7.use command: mv wordpress/* .. (unzip after all files move to html directory)

8.back up directory(/var/www),execute chmod -R 755 * and chown -R www-data:www-data(if apache also apache:apache) *

9.ok,next open /etc/nginx/sites-enbled/default,find servername choose,input you domain. E.g.
servername xxx.xxx

10.great,let's we are login mysql,create one mysql database.

mysql -u root -p
password:

mysql > CREATE DATABASE wordpress;

mysql > exit

11.all is ok,you can open you domain start install wordpress process.

so,install openvpn and wordpress can use not same port.

Tips:this is install openvpn scrpit.

https://github.com/Nyr/openvpn-install

You should do a speedtest before and after installing OpenVPN. It is the speed of the droplet serving the internet that I am referring to, not the speed of the VPN. The trick is to make sure your website doesn't use the VPN tunnel.

I have openVPN running on FreeBSD. I managed to improve the speed of the website, but never got it to the bandwidth prior to installing openvpn. Since I haven't exactly got things running perfectly, I will spare you my firewall tricks. But my plan is just to buy a $5 from DigitalOcean just for the VPN, keeping it separate from my webserver droplet. One advantage to this approach is you can do some DNS filtering of advertisement networks, filter countries you never plan to surf, etc.