Hello there!
As per my knowledge and understanding between Java and JavaScript is that, JavaScript is scripting language and you can only run the JavaScript codes on a browser while Java is an object oriented programming language where you can create an application and run it on a virtual machine.
So regarding on the installer naman, you can use NetBeans IDE or Eclipse IDE or DrJava or JSource or JDeveloper. those examples are called IDE (Integrated Development Environment) so sila yung nagseserve as working area mo for developing java application/program. Right now i'm using NetBeans, for some reasons i like the environment here. Kung gusto mo naman yung Eclipse, maganda din yan. Ginamit ko din yan dati sa thesis ko, kasi sa eclipse you can also create mobile, desktop and web applications. Kung beginner ka talaga meron din naman DrJava which is for students talaga.
Kung willing ka talaga matuto ng java, madami din tutorial sa youtube. and speaking of, you can subscribe on my youtube channel, kasi sa daming ng nagtatanong sakin about Java NetBeans i decided to create a java video tutorial channel on youtube. just search liyagreys the subscribe and hit the bell button to get notified for upcoming videos. Pwede kang magrequest sakin ng topic about Java NetBeans and i will make a video tutorial for it.
Let's learn Java NetBeans together bro.