Basically I want to learn how to use the kerning, spacing, ligatures to make it more legible. If any one knows any tutorials or guide available online please let me know.
If you're a beginner, I actually DO recommend you start out with something simpler and cheaper. Fontlab and Glyphs are awesome programs, but they're also expensive and have loads and loads of features you might not need at the moment.
Some lower-budget but competent font editors:
All these should more than cover a beginner's need. If you're serious about designing typefaces, you can upgrade to a more advanced tool.
And to get help creating a really good font I'd suggest joining a great forum like Typophile. There are many experts and world renown typographers there that give practical advice and help to others. They'll give you constructive critique of your work and help you get the most out of it.
With Typophile offline, and all signs point to that being permanent, I would recommend visiting "Phinney on Fonts". That is Thomas Phinney, type designer and enthusiast and president of FontLab. His site features some great tutorials, links to other important sites, lists of must-have books on the subject, and more. He is also a member here at the Graphic Design StackExchange. You should also check out the FontLab Videos YouTube Channel, for his free video tutorials (and other authors) on learning the skills you are talking about in FontLab.
Other resources include the official FontLab forums: everyone there is super friendly and knowledgeable—the Manuals and Tutorials on the FontLab website, and paid courses with sites like Lynda, Udemy and the like.
I would not recommend using anything but FontLab Studio or Glyphs—Fontographer does not support opentype features or kerning tables. I haven't personally tried Glyphs, but I hear good things. FontLab has been the industry standard since 1993 in one form or another (it's changed hands between 3 or 4 companies since its inception).
To add to the above—you can create your original art in another application, such as Illustrator, then import. I've used FontLab Studio to create type this way, and is a good way to gain familiarity with type design. Once you become more comfortable with FontLab, though, it probably will be better to start there first.
As to the costs, well, it depends. $600 for FontLab may be a bit steep, but consider the time/use you will expend. Having a well-functioning tool may be work the cost of entry, if you plan to be doing more type design work.