Is there a tool or does anyone know how to get the sprites and level maps out of a rom?
Sprites: Any emulator with a "pattern table" view (such as Nintendulator) would do, but they might appear slightly scrambled. An emulator designed for ripping sprite sheets could watch a game and could log all sets of OAM entries that overlap or touch on an edge.
Level maps: No. They're compressed with a proprietary method in the vast majority of ROMs. One could build a tool to watch nametable updates as new parts of the map scroll into view, but all that will give you is the physical appearance of the level (for example, the part here looks like a brick), not the logical structure (e.g. the part here is a breakable brick or a brick with coins).
You could look at sprites via YY-CHR, although they will not have any color.
Yeah, there is no definitive solution for the level map case, because each game uses a different level format. Only games from the same company *sometimes* share level formats, so it's not possible to code generic tools for that purpose.
One common way to rip level maps (i.e. images of what they look like) is hacking the games so that the camera is directly controllable. Then all you have to do is scroll through the whole thing taking screenshots. You have to study each game you want to hack in order to know what to change, and this isn't a very trivial thing, specially if you are not a coder.