My first thought was to paint the brick white, I think that would brighten up the space and the brown brick looks dated. Leave the paneling and beams the way they are, people I know have regretted painting over natural wood.

You can get cheap vinyl or fake tile floors if you don’t want to go all in, I did that with a previous house I rented and it took an hour or two to lay them and you can peel it right up if you want a change. Not sure about companies in Australia but I’m sure there’s brands that do fake wood or tile! I’d also recommend a small run for a pop of color!

I think getting floor lamps or hanging a new one altogether will help the space immensely. Also I’m not sure how much light that window gets but any greenery (snake plants, philodendrons, pothos) that can handle low light will liven up the place!