get in my car and no power at all happens randomly

Try removing the negative and then positive battery cables. Clean the posts and inside cable ends really good. Reinstall and tighten. See how that works.

In the main under hood fuse box , check that ALL screws you see for the main 'multi-fuses' and positive cable lead are clean and tight.

my car shuts off while driving at normal speeds. will start up once it cool down. it may not happen again for 2 week and then the problem repeats itself. what could be wrong