An other option would be a P2P trade, for example trough localbitcoins, but beware of scammers!
Yep, and as a brand noob, I highly suggest
not doing a deal on this forum as this section is riddled with scammers. You may already have been contacted via PM by a scammer saying they can sell you bitcoin for cash... don't do it!
Your safest bet is a highly reputable crypto exchange as was mentioned earlier. In addition to Binance, Coinbase is a good place to go. It depends on where you live, how fast you need it, and how much you are looking to buy. Binance is the easiest on an international level in my experience. Coinbase is the best for those in the U.S. and Europe, so long as you don't mind providing them with KYC information.
From what I've heard the Cash App also works really well.