D'Addario XLs are a great place to start a string journey. They're a nickel-plated roundwound that are middle-of-the-road in terms of warmth/brightness. Start with standard gauge 45-105. They're definitely a jack of all trades string. Musicians in several genres use them.
From then on, experiment with materials, gauges, and winding types (e.g. roundwound, pressurewound). I like D'Addario strings because they sound good, feel good, come in a variety of styles, last a long time, and are easy on the wallet. This is important since, well, bass strings cost at least 4x more than guitar strings.
Changing strings is probably the least expensive way to alter the feel and tone of your bass. It's easy to get caught up in the hype of changing pickups or getting a whole new bass with different woods in that elusive quest for "the" tone, but sometimes all it takes is a new set of strings to make a difference.
And remember, my ideal string may not be yours. Everyone has different body chemistry and strings that last forever for some people die quickly for others.