What is the most essential and easy to learn language

Interesting question:

Most languages are object oriented and the most used are probably Visual Basic a variant of C, like C#.

Pascal is a very structured language and is good place to get started. It's best used to teach concepts.

LISP is a language based on recursion and is probably one of the hardest to learn.

I have programmed in COBOL, ALGOL, PL/1, BASIC, APL, FORTRAN, C, PASCAL, LISP and various assembly languages.

I'd consider these in some sense "essential" but you're likely to get a different answer depending on who you speak to:

* Non-web development: C++
* Web development: PHP

Both Pascal and Basic were designed as teaching languages, so they are as KISS says, great starting points. LISP is used mostly in academic contexts so I wouldn't recommend it for a beginner. C# and ASP are used by Windows programmers, C++ and PHP mostly by non-Windows programmers. So your choice of starting points may depend on the industry you want to work in.

If you might be interested in a career in software, a couple of phrases to keep in mind are object oriented programming and agile programming, both of which are hot right now. One of the hot areas of research in web programming right now is AJAX (note that OO programming, agile programming, and AJAX are all approaches or methodologies rather than programming languages in & of themselves). C++ is an object-oriented language which is why I recommend it (though you can do object oriented programming in any language, even LISP).

If you're interested in web design, you want to also know HTML, CSS, javascript. Be sure to add a review of software design and testing methodologies to your list of things to study.