Recommendations back to Spain

For the end of our post-compulsory secondary education, we have thought about taking a tour of Spain, leaving Madrid and exploring the upper half of the Iberian Peninsula, starting by passing through Castellón, going up to Barcelona and passing through the upper provinces until we reach La Coruña. from there to Cáceres and return to Madrid, all accompanied by passing through the respective tourist sites and the best routes and landscapes.

Since I feel that we will not be the first to do something like this or there has surely been a tourist who has already done it, I asked if someone could help me or give me advice on making this trip.

Any data, advice or information is useful 😉