So far I only know very little of HTML, I'm very motivated and welling to do whatever it takes to learn (HTML,CSS,JS) where to start?
some friends of mine suggested that I start with Web development, but I have no experience at all in this. I quit my Job 4 month ago as a mechanical engineer
If you could recommend me the tools to use, Would be much appreciated.
Thanks much
i would say just follow the freecodecamp curriculum to get started with web development and watch some youtube tutorials you can also learn from udemy courses good luck 
i just finished my html and css chapter from freecodecamp
First of all welcome and good luck!
Download any text editor that your friends recommend (Iām using Sublime text editor)
Make a good coffe 
and just follow the FCC curriculum 
I recommend to start with the Responsive Web Design Certification.
And you always can get help here in FCC forum.
Good luck buddy!