I won’t address the other questions since a few have replied and given you some direction (I will advise you to avoid Thorsson and his ilk like the plague) this is about runic formulas specifically.
There are a lot of made up answers here and speculation and if that’s what you’re going for then that works. However if you want to stick to the most authentic version you can send me a message.
I won’t put the numerous formulæ down here because why give those who pretend to know this stuff any more actual material they can pretend to understand?
Three of the most basic formula are Alu, Laukuz Alu, and Lina Lauker. These are found on runic talismans (taufr) and weapons in many places. There are hundreds of formulas we use.
Some for health, some for fertility, some for wealth etc. These mainly were born out of the vitkar of previous ages writing down what worked (Laguz, Berkana, Laguz as opposed to Laguz, Fehu, Laguz and on and on)
The formula are already created for most things, if you want to make your own formula that is a bit more complicated process but send me a message with what exactly you are trying to accomplish and maybe I can help.
The method employed (rist the runes in tines, taufr, bone, rock [never paper, paper is moot]) determines the rune method used(rune, bindrune, formula, galdrastafur)
Hope that helps