I would suggest a copy of The Radio Amateur's Handbook.
It has hundreds of circuits that can be copied to implement your requirements, and also serves as a very useful source for a theoretical treatment, on a level which you might find helpful.
It also has sections on data transmission from the simple OOK technique which you propose, to more sophisticated circuits using other techniques, such as FSK, which offer some advantages.
This book is published every year, with changes and updates, by the American Radio Relay League, in other words, "ham" operators. You might enjoy this as a hobby. I started in high school 50 years ago and have been building stuff ever since.....
Good Luck, Andy W4OAH