Whats going on in the USA with Donald Trump please?

In the U.S., there is a multiple stage process.

First, like in Australia, it takes some time to finalize the vote count.  

Second, for President, the election is actually two stages:  in stage one, voters select individuals to serve as electors.  In stage two, the electors vote for president.  Both stages have to be counted.  While, enough of the first stage vote was in within three days of the election for every rational person to know the winner, the final count on the second stage was what was certified yesterday.

Third, unlike parliamentary democracies, in which the head of state names the presumptive winner to take over as head of government within days of the election, in presidential democracies like the U.S., there is a pre-established date for the new President to take over.  Thus, even though Joe Biden has been president-elect since early November, he will not actually take over until January 20 (which is actually an improvement from the original date of March 4, but moving it up took a constitutional amendment).  

As to Trump, he didn't tell his supporters to storm the White House.  He told them to storm the capitol.  To put it in equivalent terms for Australia, he told his supporters to storm our equivalent of parliament.  The White House is the equivalent of the Prime Minister's residence. 

Trump's statements are borderline on whether or not they were criminal.  The capitol is usually a public building.  (Currently access is restricted due to COVID.)  And some of his statements can be read as simply encouraging his supporters to go to the public area of the capitol to observe Congress's counting of the votes.  There are other things that Trump has done during the transition -- like contacting state election officials to see if they could adjust the count -- that are more likely to be the basis of a criminal charge.

Hi Tmess2 thankyou for the very detailed answer. I do not fully understand US politics but Donald Trump seems to be always causing a ruckus lol wow I just saw on twitter pink told him to f*** off.. one of my favourite artists but there you go.. such hate and division and there should be more peace and love at this time!

Anyway thanks for explaining it well :)

Yes Trump is still the president 

and YES JOE Biden win 

NO JOe Biden was not there when the White House was attack 

Yes its Trump who as orchestred all this chaos 

NO Trump will not face charges