I used to ride my dad's old bike, but got put off by the standover height, which was just a bit too tall. I had to have the seat all the way down to ride it, and couldn't stand with both feet on the ground. I'd still be riding it now if it wasn't for the danger of injuring myself if I fell off the saddle for any reason. I now use a bike with a step-through frame so such issues aren't a problem for me. I'd aim to have a standover height of less than your inseam, or equal to it as a maximum. If you don't mind wearing platform shoes, that's one option to get a bit of extra clearance

As 531phile said, if you want a more upright riding position, raise the handlebars. The saddle height depends on your leg length, from that you should adjust the handlebars to get the posture you want.