I just bought a Canon EOS 200d or sl2 with single kit STM lens (18-55mm) . Is it enough for a beginner? Or should I also a buy 55-250mm lens now? If yes, then shall I buy IS ii lens or STM? I want to buy at cheap price.
Do you understand what kind of photography you want to do, what the limitations of the kit lens are, how the kit lens is going to hold you back and how the 55-250 would solve those problems?
If the answer to any of those four questions is "no", then certainly don't buy anything. It may be the kit lens is all that you need given your (current) skill level. It may be that you don't actually want a telephoto zoom - you might want a fast prime. You might want an ultrawide lens. You might want a better normal lens. You might actually want to invest in lighting gear instead. Etc etc etc.
Only once you understand the problem you're trying to solve and how the bit of kit you're considering solves that problem should you even consider buying it. Anything else is just a waste of money.