Need to understand gulp - gulp

Question

I am new to gulp and i am getting object expected gulp error, but found solutions as rename file to gulfile.js
1) Need to understand every project has only one gulp file thats gulpfile.js? If i need to define more than one then how to and what will be the file name.
2)My requirement is to concatenate more than one less(convert to css) & js file into one and then apply it to index.html
3) I am using express to create gulp project structure. is this standard way? if no then how do i?
4) everytime i create gulp skeleton, do i need to install all packages again for every project?
Any references from where can learn gulp from basic.

Answer 1

I think one of the reasons you're getting downvoted is that on SO each question should be one question. This should really be four separate questions. Another reason is you haven't provided any of your code - add code (the { } icon) and include your gulpfile.js and your package.json.
1a) Yes, it has to be called gulpfile.js
1b) If you search SO and google for "multiple gulpfiles" you'll get a lot of solutions. If none of them work for you, let us know what you tried and what went wrong. But just so you know, it's better to start with just one gulpfile - it can be hard to get multiple gulpfiles working correctly, and using just one will help you learn gulp.
2) you'll need to use gulp-less and gulp-concat to turn multiple LESS files into one CSS file, and gulp-concat again to turn multiple js files into one.
3) You can use express, but you don't have to do. It depends what you're doing, and we have no idea what you're doing.
4) Not sure what you mean by "gulp skeleton". If you mean "Do I need to run npm install for every new project, yes you do.
5) Google "learn gulp"
6) If an image could just be text, it's better to just include the text.
If you need to, open new specific questions. For more on writing a great SO question, see https://stackoverflow.com/help/how-to-ask