My son started drinking from a straw at age 1. We bought him a juice box that comes with the really tiny straws. We put the straw into his mouth and pushed on the juice box to get things going. He then took the juice box from us and it just started pouring juice into his mouth. He got the idea.

Thank you for all of the feedback! I had some partial success cutting down a straw so he had less sucking to do to get what he wanted. That was a great suggestion. He still wants to bite down on it though, so I may need to try cutting hard straws down. We're starting a weekly joint OT/ST session in September so maybe they'll have some suggestions, too.

My son, now 7, didn't really use a straw until he was 5 and a half or so. He also mainly likes water and that's really great! I know tons of kids that won't drink water at all and it really is the best for you. We would try straws from time to time, but not push it as he wasn't ready.
Spitting took a while too, but once he did get the hang of it, he wanted to spit all the time. We brushed our teeth together and modeled it for him also. I think that helped a lot. We made a "puh" sound as we spit and he loved that.
We used non floride toothpaste until he could spit. Well, we still do as he still swallows some of it. Good luck!

Crazy straw is a good idea. Blowing bubbles in milk is always fun too. The concept of blowing is the reverse of sucking and he will need to secure his lips on the straw to blow bubbles. Then you can teach him to reverse it. Just my thoughts.Spitting is a different one, but I would satrt with a piece of paper and get him to "blow" it out of his mouth (spitball style)

Bubble tea straws are larger straws which will require more suction. They say to go smaller and thinner.