After not riding for 25 years I bought a bike from Amazon that cost 300-400. I didn't know exactly what I wanted but it was a bike that was around my size which was small.
After a year of upgrading parts and figuring out what I liked I saved up for the bicycle that fit my needs.
Starting out with a 300 dollar cheapo from amazon is not a bad thing when you have very little idea what you really like and the bicycle industry has changed multiple times since you were last on a bicycle.
I bought a single gear fixie/freewheel bike. It was similar to https://www.amazon.com/Sol%C3%A9-Bicycles-Blanco-Single-Speed/dp/B08W2QC4ZN/ref=sr_1_17_sspa?crid=H4CUZ1ZE16SN&keywords=bicycle&qid=1649756398&sprefix=bicycle%2Caps%2C117&sr=8-17-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzTDAyNExERDMwQzRWJmVuY3J5cHRlZElkPUEwNjAzODg0MzI4RkJMWjZYRjFESCZlbmNyeXB0ZWRBZElkPUEwOTU2NTAwWUZKOE5NV01CS003JndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
I should note I looked around for any bicycle my size but couldn't find one, new or used in my area so just went with Amazon (and even then it was slightly too large for me).