I don't have any videos but I'll briefly explain: basically there are a few that get cited in the news. Newspoll is conducted by The Australian, but then republished elsewhere. Guardian Essential Poll similarly - but for The Guardian. And Roy Morgan also does opinion polls - though less regularly (fun fact: I worked for Roy Morgan doing opinion polls very briefly in my long list of previous jobs). Anyway, so the polls can have multiple questions. The publications choose them, so this means some can have leading implications, or some are just consistent regular ones like "out of the two major parties which are you most likely to vote for?" (hence we get "two party preferred" results - even though a large chunk of people will vote for minor parties/independents). The actual polls themselves are conducted by YouGov, which you can sign up for, and can select from 9 million people to be part of the survey. They also will have demographics data for different areas to try and make sure they don't end up having 50% of their results from like 65+ year olds if they only are 15% of the population of a general area they're conducting the poll in. The thing is: these polls tend to only cover the opinions of 1000-1500 people at a time, so it's not like every month they're asking 1 million people and hence why a lot of people will go "I've never been asked." It's a representative sample, and so has a margin of error (usually like 3% either way for how people will vote) - but they usually are very good predictors of who will win an election if there are long term trends in them. Though, as we saw with the 2019 election, they're sometimes wrong. They also are used to gauge public opinion on all kinds of topics like healthcare, climate change, etc, not just "who do you like best?" So it's useful data for parties to know if their policy pitches are working or if they're in need to change their tactics to retain public support. So they're useful, they can either re-affirm a government's decision or put pressure to change it, and they might indicate who will win the next election - though opinions can change a lot depending on what happens in the next few weeks.
If I was living in SA, I would vote for Peter Malinauskas to be my Premier. I would be at peace knowing that the Premier has two massive guns that he can defend the state with. 💪🏽