Long time ago I took one course of C+, I liked it but did not continue, now I am thinking of Java ( self learning).

no so difficult if u like programming and able to implement your logic. just learning core java is not enough for the job market you will have to learn java frameworks too. 
thenewboston.org/tutorials.php - follow this guy for core java
javabrains.koushik.org/   - follow this guy for learning frameworks

 If you able to understand very basic fundamentals of this.javaProgramming, it will be a peace of Cake, otherwise it will be a big rough mountain with so many painful sleepless nights !!!!!

Thank you all, one last question.
I have a brocher for adult learning and offering these two courses, I can take one and is it going to be helpful for java?
1) HTML and web design,
2) web design with dream basics?
Please no fun on my lack of cumputer knowledge.

 @magorkhe1 tbh neither of the course is going to help you learn java but if you only have one from those two then i would suggest you go for the first one HTML/Web design. You will at least get to know coding the HTML tags.

If you have already learnt C++ it is pretty similar to JAVA but my question is why do you want to learn JAVA?

I took Java classes and C++ classes but felt like Java is very very complicated then C++. I can understand c++ but cannot understand java at all .

 Java is very hard ..You may be able to wite "Hello World " but ..it is very complex u need to have strong OOP skills and understanding...