Are there any territories where German and Spanish are official language?
I don’t see any overlap there. Several South American countries have a German diaspora, but no official status. It does appear to have some kind of official status in some parts of Brazil - but there of course it’s with Portugese, I don’t think Spanish has any official status. I’m surprised to discover that Spanish has no official status in the U.S., or even at a state level in New Mexico; German certainly doesn’t.
Not even English has official status in the United States. English is the language used by government de facto. But there’s no de jure national language.
A lot of government services are provided in multiple languages depending on the demands of the relevant constituency.
Historically it did have a requirement in the New Mexico State constitution, which was for a fixed period, renewed repeatedly, but finally allowed to lapse. There are still protections for Spanish speakers, but, as noted, there isn’t really an “official” language status in the United States.
For more reading -
On November 7, 1911, the electors of New Mexico approved a substitute provision on the amendment process. On January 6, 1912, President Taft signed the Statehood Proclamation.
The Mexican Americans of New Mexico succeeded in protecting their heritage by inserting provisions in their constitution which made Spanish an official language, equal to the English language. The constitution also provided that, for the following twenty years, all laws passed by the legislature be published in both Spanish and English, and thereafter as the legislature should provide.
Or for somewhat easier reading.
https://www.abqjournal.com/208492/spanish-not-enshrined-as-official-nm-language.html
English is the official languag3e of the state of California and has been since 1986.
Here is a list of US states and their official language(s). It has some interesting information. For example, English is not the official language of Maine; however, Maine does have an official language for their Deaf community (American Sign Language). Also, Hawaii has two official languages: English, Hawaiian. Sadly, Hawaiian Pidgin isn’t on their list of official lingos.
Officially, no, but parts of Mallorca probably qualify from a de facto standpoint… 
There’s a town in southern Chile where many still speak German. And, a few places in Paraguay, I’m pretty sure.
Then there are Mennonite communities in Belize, Bolivia, and at least two parts of Mexico (Chihuahua and Campeche). I’ve heard German on a radio station in Hopelchen, Campeche, Mexico, where the Mennonite population has grown in the past 20 years. Many villagers around them also speak Spanish as a second language…because they speak Yucatec Maya at home.
At the time of the collapse of the remnants of their empire in the late 1890s Spain sold off its lesser Pacific domains (Marshalls, Carolines, Northern Marianas) to Germany, but these (a) were barely used as fleet supply stations and trade posts with no real persistent society-building by Germans, (b) had not been treated that much differently than that by the Spanish either in the prior couple of centuries, and (c) were taken over by Japan in WW1, and then by the USA in WW2. The language of the New Boss successively took over as that of officialdom every time AFAICT.
For a more serious answer, perhaps the OP might consider the territory (well, buildings) held by the European Parliament in Strasbourg, Brussels, and Kirchberg, where Spanish and German (among other languages) are co-official. These territories don’t have their own separate jurisdiction, but they are operated by an internationally recognized polity with legislative power.
A story which periodically pops up in German media is that of Thälmann Island, an island off the coast of Cuba which purportedly was ceded by Castro to East Germany in 1972 as a token of Socialist friendship between the two countries. The act is, however, seen as merely symbolic and not an actual transfer of territorial title '(and both the German and Cuban governments are in agreement on this).
Stumbled across an Amish/Mennonite service in the jungle of western Belize. Thought we had been transported to Lancaster, except the buggies had wide tires instead of the skinny one for American roads. Horses looked about the same…