I disagree.
If you've never tried it before and don't know if you will even like it, the first thing is to get hold of anything and go down, get on it and get wet, even if the gear is hopeless. You might only use it for a month or two and then get something better, but you have to start somewhere and I think you want to start now. Start with what you've got.
Yes, you might be put off it, or you might see that it's lots of fun and you need better gear, in which case you will then have some incentive to beg, buy or borrow something better for the job.
Years ago I learn't on the oldest most crappy gear and I had the best fun for two summers. It was almost for free.
It took me two summers to get up planing in the straps because the first summer was spent falling in. It was all lots of fun.
If you've got buckets of money then fine, go out and buy the latest and greatest, then if you don't like it you can store $2000 of gear in the garage for a few years until it's worth nothing and then sell it on ebay for $150.
If you don't have buckets of money then get whatever you can and give it a try.
And yes, you might get put off it because it's too hard. But then if you wait until you can afford the best gear you might also never get around to it because it's not worth spending that much money on something you might not like.
When the itch first starts, scratch it with whatever you can find before it goes away.
Keep in mind that when that old gear first came out it was the cutting edge of windsurfing technology and everyone raved on about how good it was. (

people raving)
Thousands of people learnt to sail on it and most of them enjoyed it, including me.
Just because it's no longer the cutting edge doesn't meant it's good for nothing and no longer fun.