Lost all power need help

So I just bought a 1970 Duster 340. I took it out today for the first time since I purchased it and I lost all power. I got on it a little bit then everything shut off. I have no lights no nothing. What do you guys think the problem is? I think it might be the fusible link? This is my first classic car so I'm not really sure. Any help would be great. Thanks.