Changing oil is pretty easy.
You just need to get an oil drain pa, oil filter wrench and a wrench or socket and ratchet to remove the oil drain plug.
If your car needs to be raised up you can use some car ramps to raise the car up on.
Then just remove the oil drain plug and allow the oil to drain into the oil drain pan.
While the oil is draining out you can then remove the oil filter using an oil filter wrench or some channel locks.
You remove the oil filter by turning it counter clockwise and to install the oil filter put it on by hand and hand tighten it by turning it clockwise.
Make sure put some motor oil on the rubber seal of the oil filter so that it seals.
Then after the oil is drained put the oil drain plug back in the oil pan and tighten it.
Then add oil and start the engine and let it idle for a few minutes and remove it from the ramps and let it sit level.
Then shut the engine off and allow it to sit a few minutes and check the oil level again.
If it needs some additional oil add a little at a time and then check the oil again.
Motor Oil in a car or vehicle typically lasts for 3,000 to 5,000 miles before it goes black and dirty and needs changed.
I change my oil every 3,000 miles which is about every 6 months of driving for me.
I work from home so don't drive that often but when I worked away from home I would rack up 1000 miles in one month or 3000 miles in 3 months so my oil needed changed more often.
As long as you're changing your oil every 3,000 miles to 5,000 miles your car should be fine.
Also always change the oil filter every time you change the oil as the oil filter gets dirty as well and they are cheap and easy to replace.
Motor Oil that has never been opened can last for years because it's actually old to begin with but it has been refined and formulated for the engines.