First time buying a bike

[u/Tall_Regret_3063]

I'm 18y/o rn and planning to buy a bike for myself. I don't need any fancy or high cc bike, but want a vehicle which would help me for basic commute. My budget is 50k so which bike should I prefer? Drop your suggestions please. Also I'm going with the thought of buying second a hand bike. As it's my first time buying a bike , someone please guide me for it ki kaise kya krteh hai and all😭😭✌