Can someone double check these answers?

Regarding allele frequencies, genotype frequencies and hardy-weinberg.

Here is the question: https://imgur.com/MVIUPol

Here is the data about the population: https://imgur.com/Ha8onyd

Here is the answer for California part: https://imgur.com/ZpWRpqB

Here is the answer for Nevada part: https://imgur.com/XDH4DMm

First the question asks about allele frequency for California. This one is easy calculation, for G for example we would have 2(12)+ 1(6)/2(30) =.50 for G and 1.0-.50 =.5 for g

Now my confusing is about the genotype frequency, can't I just divide each genotype by total of individuals and that would be my observed? The answer above shows smth else... It shows them using the hardy-weinberg equation for the observed, I thought we use that equation for the expected?

Anyways in the answer for california, they get genotype frequency of 0.25 for GG, 0.50 gg (eventhough going based off their logic it should be 0.25 not .50) and then 0.25 for Gg (which should be 0.50 right?).

I am kind of confused cos it seems that their is two different ways to calculate the genotype frequency their is the observed frequency and the expected.

I thought for the observed its # of genotype / total individuals aka for Gg we have 12 of them so 12/30 = 0.4 observed frequency Gg

Now for expected genotype frequency I can refer back to the allele frequency of G to figure out expected frequency of Gg which would be 2pq so I get

2(.50)(.50) = 0.5 expected genotype frequency for Gg

Did I calculate the observed and expected genotype frequency correct?

Also if my chi-squared (X^2) is 2.9 and it says for test with 2 alleles and three possible genotypes, there is 1 degree of freedome. If X^2>3.84, the null hyptoehsis of Hardy-Weinberg genotype proprotions can be rejected"

The wording is kinda confusing and my stats are kinda messed up, but does this mean that says 2.9 is lower then 3.84 therefore the null is retained so that means that yes the population is in hardy-weinberg equilibirum or that means its not?

What does rejecting null vs not rejecting null mean for hardy-weinberg? Is the null means population is not changing and its in equilibirum and if we reject it it means we are agreeing with the null?