British passport & citizenship?

Hi,
Wanted to get some confirmation as I'm a little confused about if I'm a citizen and getting a passport.
I am over 18, born after 1983, born and live in Australia to a British born mother (she came to Australia in the late 60s and was a permanent resident here until getting her australian citizenship just a few years ago). My father is australian, not listed on my birth certificate. From what I can find out I am a "British citizen by descent".
My question is, I am currently living in Australia, and I do have a plan to possibly go live in London next year, but nothing concrete yet. Can I apply for a British passport while I'm here in Australia (or apply for my citizenship) without previously living in the UK for 5 years? I can find info about being British by descent but it gets confusing regarding where I currently live and where I intend to live...
Also if I was to apply and get my British passport, is that all I need when I come over to live in the UK? Or would I also need a visa or citizenship ceremony before coming over to the UK?
Thanks so much in advance

As you are British by descent (assuming your mum was born in the UK) you can apply directly for a passport, no need to have lived in the UK at all and no need to attend a ceremony either:
https://www.gov.uk/overseas-passports
Overseas applications can take a while (sometimes 6-12 months) so you may want to get it done as soon as you can so you've got the passport ready for when you travel to the UK

Oh excellent! Thanks so much for the info. It's gets all a little confusing trying to read over all that info on the UK home office website!
I'll get on to the passport asap!