J.R.
Hey Auntie K.,
I wouldn't worry much. A lot of things like this also depend on size. Big kids sometimes have a hard time because they have a lot of weight to lift and balance. But small kids can have a hard time too. Sometimes they can do something but don't want to. My little guy could walk for a few weeks before he really did it much because at that point crawling was a lot easier and quicker. I wouldn't worry much about talking, he's much too little to expect anything right now.
Remember that all kids progress at their own rate and some do things earlier and other things later. A friend may have a talker while you may have a walker, but not at this age usually.
As long as he's sitting up and crawling right now he's fine.
Jen