My first thing would be get your firewall active. cpHulk is ok if you have WHM, on a non panel server CSF is best imo.
After that configure what services you need, all you can do then is make coffee and watch process jumping around in Htop. Monitoring is important with a new VPS in my experience, servers experience problems sooner rather than later.
Depending upon the VPS plan , I will first check if I have received the resources that the provider has shown on his website. Like SSD , RAM , CPU etc... once thats confirmed , as other said I will install control panels , security , hardening , optimization etc.. will be done.
As describe above, firstly I would also confirm the server resources like memory, CPU...etc.
Secondly, will install the required software apps or control panel and firewall (mostly CSF) and changing of SSH port.
Before to upload or install any other files/applications, I will setup a automated backup, so now the server is ready to test any website before to go live for production or host web apps.
I have experienced instances in which IPv6 has caused network problems, so the first thing I would do is temporarily disable the IPv6 and install the required updates and software, after that disable root and change the SSH port.
first I will update the server with all the latest updates.
Change root password.
change SSH port.
change mail port.
then install cPanel/WHM.
Install CSF for cPanel.
Configure the main apache with a couple addons.