Yes, you do need a license for a moped under 49cc, if it's over 49cc, then you need to go through the hassle of registering it as a moped/motorcycle. And as far as I know in FL law ,there is no such classification as a motor assisted bicycle, the main rule for anything motorized like ours is the 49cc rule. I live in FL and the cops around here don't really give any attention to you as long as you aren't going rediculously fast or openly breaking traffic laws.