before, everyone said 50mm f1.8 is a must have
Really, the f/1.4 variant is the must have, but we're not going to blow half your lens budget on something that, while definitely very nice and would work well with what you do, will not cover *everything* that you want to do, so we're skipping it in favor of 1 lens that will do what you want to do. Even if you went with the f/1.8 variant for only $100 or so, well... see my recommendations above, I was stretching your budget as it was. If you find yourself able to afford one though, you should definitely pick it up afterwards.
imo, being stuck with a prime as your only lens is too restrictive as a beginner.
Incorrect. Sticking with primes as a beginner forces the beginner to learn to compose with his feet instead of with his hand controlling the zoom focal length. It removes 1 of the options available for affecting composition (zoom) and thus forces the beginner to be more creative as well as making it easier to focus on other aspects of the photograph.
If the beginner wishes to do both landscapes and portraiture (for example), then he would be well advised (on full-frame) to buy a 28mm f/2.8 prime as well as a 85mm f/1.4 prime.
Zooms are for 2 groups of people: those too lazy how to compose correctly (stereotyped as the average joe who not only doesn't know better but also can't see the IQ differences between a prime and his kit lens), and those who know how to compose correctly (stereotyped as the professional, since professionals understand that both "zooming with your feet" and changing the focal length are key to getting proper composition.
Zooms are not for people who wish to learn.