I've been dancing awhile and it has taken me a long time to find the right shoes. I'm opinionated about it now.
Your shoes are very important. Don't skrimp. I had no idea they mattered so much. They will change how you dance and when you find the right pair you will never go back.
Go to a ballroom shoe store and let a professional help you chose the proper pair. It's the only way you are going to get the right fit and they don't fit like your normal shoes fit. My ballroom shoes are 4 sizes smaller than my normal shoes and I need to go down one more size now that I've gotten used to the tightness. They should fit like a second skin and they will stretch as you dance. They have to have flexibility in the sole which your cheap shoes just won't have.
Me...I prefer DanceNaturals because I have thin feet. Ray Rose are wonderful and some of them have been designed by top level dancers to be perfectly balanced. They instantly changed my own balance.
Buy good shoes, don't buy cheap shoes and don't get them until you've tried them on and had a professional evaluate them and take them for a test run.