It doesn't necessarily need replacing because of a split. It can affect the sound (and usually does), but may well remain playable. In the past some players used to partly split the reed with a razorblade to get that sound. I'm not sure how many, if any, still do this, though.
You might want to consider using a synthetic reed or a Rico Plasticover, which is a regular reed with a thin layer of plastic over it, if you've only just started. That way you can at least rule a bad reed out of the equation. I've only recently (after 6 months of playing with only synthetics) begun experimenting with cane reeds again. Now I can at least tell which reeds are good and which are not so good.
I still like the sound of the Legere Signature Series 2.5 (tenor) the best. It's quite dark and doesn't have much of a buzz like so many other reeds do.
Reeds are very much a matter of personal preference, but I'd suggest trying out a synthetic if you can. They might seem expensive at first, but think about this: I bought my Legere reed for 25 euros half a year ago, and have played it almost exclusively, perhaps 95% of my total playing time, and it still shows no sign of wearing out. How many cane reeds would I have gone through in that time? Probably more than a box of ten, which is roughly the same price as the Legere.
They don't need soaking or warming up. They don't require as much cleaning either, since even if it grows something nasty on the surface, you can wash it away. I don't even take the reed off the mouthpiece, except for maybe once in two weeks or so. When it starts getting smelly, I wash both the mouthpiece and the reed.
Some advocate soaking reeds in gin as a better wetting agent than water, but not for cleaning as such
I've never had to clean a reed beyond a wipe with a cloth and the same goes for mouthpieces if you wipe them in and out every time you play, but if you get a crudasceous deposit inside your mouthpiece there's a whole world of tips and advice out there depending on mouthpiece material and exactly what exudate is stuck fast
The advantage of synthetic reeds leans on the fact that for a while you stop blaming the reed if some notes don't come out.
You get rid of one variable. After a while you might want to try some cane reeds and see how it goes.
As you playing skills develop, you will instinctively become more selective about which reeds play the way you like in terms of tone and resistance when you play. I would suggest sticking with major brand cane reeds in the appropriate strengths that you number and rotate when you practice.
If you learn to play on synthetic reeds which last for an extended length of time you will never experience the variations that are inherent in cane reeds that help you develop a taste for the reeds you prefer in your style of playing.