OP is at a place where I was 3 years ago, has car, knows how to drive but knows zilch about under the hood.
I suggest before you do ANYTHING, except related to safety, like tires and brakes, watch some videos that relate to your vehicle. Just put year and make, model in Youtube and ton should pop up.
Understand what is what, the function thereof, what makes it break and work etc before doing anything.
I don’t see you telling us what year make and model you have
I have 2006 sentra and I had same issue. Shocks were leaking so I replaced them and didn’t make an iota of difference in the ride quality. Replace tires, again not much of a difference. So I have realized that not much can be done without spending money (and I don’t want to spend for 14 year old car), run great for errands and thats enough for me. We have another one for longer drives.