You only need Jetpack if you want any of its features. It's part of a standard WordPress install, but you don't have to enable it.
Biggest advice: KEEP IT SECURE. If you fail to install security updates in a timely manner,
it will get hacked. It doesn't matter how small, inconspicuous, or obscure it is. Organized criminals use special tools that search the Web for vulnerable WordPress sites and hack them automatically, and then use them to plant viruses and malware, host phony bank pages, and host other content that they can not legally host anywhere.
Also, use really strong passwords for your administrator users. If you use weak passwords, again, you will be hacked--it's not a matter of if but a matter of when. I guarantee your site will be attacked.
If you run WordPress you
absolutely MUST keep on top of security. I recommend tow free WordPress plugins for everyone who uses WordPress:
1. Wordfence Security:
https://wordpress.org/plugins/wordfence/This free plugin will harden your site. It will email you to let you know of security updates, it will install an automated firewall, it will prevent brute-force hack attacks, and it will cut off anyone who tries to use a known Wordpress compromise.
2. WPS Hide Login:
https://wordpress.org/plugins/wps-hide-login/This free plugin has one purpose: It will move your WordPress login page from wp-login.php to anything you want (such as yoursite.com/my_secret_login_page). This will prevent people from attempting to hack your site by brute-force guessing passwords.
Running a WordPress installation without these plugins is begging for trouble.