What parts of the photo do you like about it? What do you want to bring out/balance? It’s pretty gimpy but I almost always start with fiddling with the exposure. If that hasn’t addressed what I like about the photo, I move on to finessing the black and white levels. if still not satisfied, have a play around with the contrast. Once you’re happy with how it’s changed, jump on over to the colour settings. This is the best bit, go wild, because you can always undo errors. Make multiple save states throughout the process. If you’re feeling it, add some grain! My photographs feel better to me with a bit of grain, and I think it can make up for any visual imperfections/draw attention away from them. But I have a huge partiality for film photography and some might say that grain on a digital photograph is insincere. Just go with the flow! Needless to say I do all my editing in Lightroom and Photoshop, but I imagine most software packages will yield you similar results once you’ve attained mastery.