Hi and Welcome
How old are the keets do you know? If you are unsure of sex, I would seperate them now, not wait until you start training as you could have accidental breeding
Honestly with two it will always be a bit more difficult to hand tame as the birds have eachother so less likely to bond with you more than the other bird...that said it can be done!
Just go really slowly, one bird at a time with the other in a seperate cage out of sight (and hearing distance). Go really slow, start by using a perch to get them to step up onto and then gradually move your finger along the perch until it's the finger they are stepping on, instead of the perch. It's important to realise if you go too fast it's like stepping backwards and it will erase any trust you've built with the bird up until that point. Go very slow, it's the key - it doesn't make a difference in the long run how long it takes, an extra week or two now for a lifetime of happy loving keets?