Hi Nat16,
Entering your dates is a crucial step and it's vital you're able to do this with ease. I'll be happy to help you get back on track so you can enjoy the great benefits of the program.
I'd like to start off by troubleshooting this issue to determine if it's a browser-related issue. Clearing cache and cookies is a great way to clean your browser allowing it to work more efficiently. Here's an article that shows you how to do that: How to clear cache and cookies. If this doesn't work, I suggest using a private/incognito window to see if that works instead. Try this out and let me know what happens.
I'll be one message away in case you need further assistance.