train form Sevilla to madrid AVE

No, it's not. What do you exactly mean?
https://www.renfe.com/es/en/inspirate/rutas/sevilla-madrid

how far in advance can I book do they accept credit cards

90 day in advance.

I'd rather leave it to your fellow countrymen to assess whether it's possible to pay with an US credit card. In any case, I haven't had any problems using my own Belgian credit card.

Reference Renfe:
You can pay for your tickets with debit/credit cards (MasterCard, Visa and American Express), PayPal, Bizum, Renfe Points, Google Pay and Apple Pay.
https://www.renfe.com/es/en/travel/informacion-util/where-to-buy

How to buy train tickets for Spain
https://www.seat61.com/train-travel-in-spain.htm#How_to_buy_train_tickets_for_Spain

You can of course buy Renfe tickets direct from Spanish Railways at www.renfe.com, in € with print-your-own tickets. Unfortunately, Renfe.com has more than its fair share of quirks and a reputation for rejecting a significant proportion of overseas credit cards. It can be fiddly to use.
Pretty much the only reasons to battle with renfe.com rather than buying easily from www.raileurope.com or www.thetrainline.com is that you avoid paying any booking fee. If you want to try using Renfe.com please read the advice on using Renfe.com below. It frustrates many people, though I have to say it has always worked fine with my own credit card and it now also accepts PayPal.

thanks for help. I have been able to book train from Sevilla to Madrid the problem is the website wont let me progress to payment keeps wanting to me to book for a return train ride what am I missing my husband and I are both looking at it....

When you click in the date section, you need first select "One-way trip" (it's by default set to "Return trip").
See this image https://imgur.com/a/WbrIGrH

Bingo thanks Windyram Belgium

You're welcome!