Unless you’re keeping live plants and/or maybe New World cichlids that utilize light cycles to spawn, tank lights are mostly optional.
Yes, tank lights help you see your fish better, perform tank maintenance, and other purposes. However, your fish mostly won’t care. In fact, you may see more natural behavior out of them with only ambient light, especially the smaller species. Another reason to go easy on the lights is algae control, including brown algae (diatoms). More intense, longer running light can easily promote algae growth, especially in tanks without live plants.
If you do keep lights on your tank, specifically strip lights, it isn’t necessary that the strip be the full length of the tank. For example, for a 48″ tank, you don’t need a 48″ light. If you only want to put a little light on the tank, go with a 36″ strip or maybe 30″. That will light things sufficiently to provide enough visual light on your livestock while allowing you to see what you’re doing during maintenance.
I have several 20g long tanks, which are 30″. I keep 18″ LEDs on those tanks, which throw more than enough light. In fact, I keep 36″ lights on my 48″ tanks.
You can certainly use strip lights that run the entire length of the tank or even multiple pendant style lights if you prefer, but they’re not necessary for you or the fish, in most cases.