Can only agree with all stated.

Buy a pup - go visit it often, speak to the rearer a lot about future steps taken, learn a lot through it. Then find a trainer through possible help of the rearer (most are willing to help) who will later take your dog, then go over weekly and have a yarn to them, learn about training and dont be afraid to ask WHY.

My mentors copped that WHY question all the time WHY do u feed that WHY do you run them this many times WHY do you do this WHY do you do that.

They were things i wasnt fully aware of and it helped me learn a lot.

Then when the time came i bought kennels, the works to get set up through the guidance of my mentors, and bought my first dog to train. Was an ok dog who i got cheap and had a LOT of fun with. Made my mistakes but upon learning over 2yrs with trainers, i didnt make any that could bring any harm to the dog. Learned my own way to train dogs and found what worked for me and the dogs.

If you take a step like this, look at what your budget is too - how much you are willing to pay per week for a trainer, unless you find one on 50/50. How much for a pup... and as a member of this forum stated and i dont think ive heard a truer word spoken.....
Greyhounds are like a bus... dont jump on the first one or for that sake be disappointed you missed it - there is always another one around the corner.

Do your study, speak to many people, make sure theyre respectable, and they can help guide you into it the right way!