Toddler Speech

I’m curious as to others experience with their toddler’s speech. Have an 18 mo and he’s saying lots of “words” (probably about 13-15) but some are soooo different from what they should be. For example, both “banana” and “potato” are “ba-gee ba-gee”. “Shoes” sounds like “dag-in”, and so goes garbage, and blanket. Other words like kitty, chicken, woof woof, yucky, Dada, meow, are much closer or almost perfect to how they actually sound. He almost never says “mama”, so both mom and dad are “dada”.

We read daily, I talk to him all day long and explain what I’m doing, point, describe, phonetically sound things out for him when I’m trying to get him to say it correctly, etc.

Is this normal? A delay? Is there anything I can do to aid his speech progression?