It has 85k miles and I need to know what parts and brand should I get as far as maintenance is concern. Like spark plugs , breakes, fluids, etc... And if oem parts is the best way to go? I know that my trailblazer only like ac delco stuff. This will be my first car that is not chevy or ford or dodge.

Also the car didn't came with a car manuel, so I need to know what type of oil and fludis does she uses? And what is the best brand to get?

 

I'm not telling you to use the search feature and start reading (although that would be the best thing to do) but opinions on this are going to be widely varied based on the mods and preferences people have.

OEM is always nice, but is not always the best option in terms of performance or cost.

I use Mobil 1 5W30. Your choice may be different. Lots of folks here love Castrol but I've used Mobil 1 for years and years and see no reason to change based on Internet opinions.

Here is the .PDF of your owner's manual. Took 20 seconds and Google to find it.