Learning to create wordpress theme with Bootstrap

I would say i came late into the world of Tech, i stated fiddling with wordpress just over a year ago and i have learnt so much. I have done quite a few sites (using themes) for friends and family and I’m in love with wordpress, however i’ve got to that stage now where i feel it’s time to develop and have a go at creating a simple theme myself.

Is there anyone here who perhaps was in my shoes and now creates his/her own theme from scratch? Kindly advice how learnt to do this and any suggestions on how to go about this please?

Much appreciated