Put it out before there were flames and unplugged everything . Replaced the fuse box now passenger headlight won't go out and tail lights won't go out. Dash lights flicker and radio flickers i have interior over head lights but it still won't start . Any idea where to start or what might be wrong. This car is my lifelines and I can't afford a mechanic ... Thank you in advance for any advice
Short circuit, loose connections and feeding high-consumption loads without proper fuses are perhaps the main causes of fuse box/wires smoke, melting and if out stopped, fire that can consume a car very quickly and up to its bones. You would need patience and a kind of CSI inspection to determine which wire or fuse in the fuse box was the principal cause of the the damage.
For instance, if a headlight's fuse was loose and because the headlights are a high-consumption load if they use ordinary bulbs, it is enough to heat the fuse socket with all it implies: heat will melt the socket, moving the wire connections, probably make them touch each other or touch ground, etc.
If you take a good look to the wires and the fuse box you may be able to find which was the principal one, because it will look more damaged than the other. This is a highly empiric way to check for what happened tho.
If you replaced the fuse box and some of the stuff are not working, you perhaps wrongly connected the feeding wires to these. Again, patience and check one by one. It is a good time also to check that all fuses, all connections and ground are properly tight (a loose one may reproduce your previous problem, also justifies your flickering radio). Check every connection, one by one, also put high-consumption loads to work and touch its fuse and wires to sense it they are getting hot. Heat is no good, if you can sense that then that part of the circuit is damaged, wire touching ground, wire having more than one load attached somewhere, etc.
However if you got such heat to almost get a fire, changing the fuse box will not suffice: you may need also to change the wires harness, not all of them but perhaps the ones involved and I would specifically change the one to the key.
Try to find your car's mechanics manual or its Haynes book, and use the electrics diagram to assist you.