Unfortunately we aren’t in a position to help people with developing fonts. There are multiple tools out there for drawing the fonts.
We have used FontLab, Glyphs, and FontForge for drawing the glyphs. Those are all good tools.
We always release our fonts under the Open Font License which is a well respected license. Google Fonts requires any font that it puts on Google Fonts to be released under the OFL. However, Google Fonts actually needs to want your font. As far as I know, you cannot just request them to add your font to the Google Fonts library.
We have also created a site called Font Development Best Practices that you should find helpful as you begin your journey.
Since this is actual the Keyman/keyboarding topic, I will also tell you that once you develop a font, you can distribute it within your Keyman package. That is a good way to make sure your keyboard has the font it needs.