In my many years of experience connecting to guides, I have formed this opinion. Keep in mind that others' opinions may differ. In this matter, there can be no right or wrong answer, just one that is more or less helpful. You get to choose!
A Spirit Guide is a helping hand in spirit from a wise old spirit when you need it, but only if and when you ask for it. If you need help and are open to receiving it, just ask for it.
When we ask, those in the spirit world come forward to offer us that help. We may also receive assistance from our own future selves, who are heavily invested in helping us.
'They all' want to help us on this Earth to move onto a higher vibration so that we can all evolve. The 'currency' in the spirit world is love, energy, experience, and information. Whenever help is given to anyone, we gain all or some of these precious things.
Moreover, your future self surely wants to help you, as their investment also benefits them directly.
Often, when we sleep, we have the opportunity to meet potential guides from whom we can choose those we deem beneficial to work with us.