(Question) Complete beginner to international flights

[Jakef]

Hi there,
Sorry if this is in the wrong forum, I'll make up for it by posting a report after the trip!

I'm going to London in January, doing some traveling and coming back in February. At the moment I'm planning on taking Emirates from Brisbane, which is not the cheapest option but I have heard good things about them, plus I really want to use this opportunity to fly on an A380. The other option is Virgin Atlantic from BNE or Qantas from where I live which connects through Sydney.

Basically the stupid question is how do connections like this work with baggage and such. If I were to fly domestically to Sydney would it mean I would need to go and collect baggage and transfer terminals myself? If I go with Emirates from Brisbane do bags get checked all the way to London, even when the BNE-DXB flight on the way there has a stop in Signapore? Their connection times seem really short as well, about an 1h30m most times...

Thanks in advance, sorry if these are stupid questions, this will be my first time flying international long haul....