Welcome to the forum! We would, however, need a lot more information to help. If your battery is dead beyond a certain point it won't even complete the circuit, so that's one thing to check. You can look for a corroded or loose or otherwise bad battery cable or starter cable. If your alternator has gone bad this could cause the battery to become completely drained. Some of these things can be checked wit ha good multimeter if you know how or maybe have a friend who does and can help. I'd say first try a different battery. It would be handy if you could get it started and be able to drive it to a shop or Auto parts store that can check it for you, such as AutoZone. Otherwise you may have to have it towed to a shop or have a mobile mechanic come to you, all of which are expensive solutions. Please let us know what you learn and how it turns out.
You can clean the the battery connections first and check where the ground cable fastens to the car.Try it and see if it makes a difference. If not, pull the battery and take it to a auto parts store so they can check it. Always check the simple stuff first.