"We went to school and then to the park."
Translation:Fuimos a la escuela y después al parque.
entonces is usually used for drawing a conclusion ie. if I have 1 lingot and you have 2 lingots THEN there must be 3 lingots.
It is also used to mean 'at that time' ie. the lessons were easier THEN.
In this sentence then means 'later on' or 'afterwards' so we use 'luego' or después.
Better question is why 'the' is not required before 'school' in English. Spanish is pretty consistent that if you go to some place, 'el' or 'la' are required. English drops it in some specific expressions like "I went to school." (likely because this sentence can also mean that I got education, rather than I visited a building) or "I went to hospital." And you have to be very careful when you have some British and Americans together when you ask "Should it be 'to hospital', 'to a hospital' or 'to the hospital'?" The spirited discussion may end up in fisticuffs.
entonces - después - luego
should después be used
https://www.youtube.com/watch?v=Elw9twiZ-eE According to the guy in this video, yes. Since anyone can put anything they like on YouTube or the internet, you always have to consider the source, but according to him, 'entonces' is not used in the past tense, but if you are speaking in the future tense, 'entonces' and 'despues' are interchangeable.
Yes and no. 'To go' (ir) and 'to go out' (salir) are technically not synonymous, although there is a certain overlap in meanings set by context. However, as students (especially beginners) we probably should stick to the more or less rigid differentiation (right until the moment when Duo inexplicably demands flexibility). So 'fuimos' is a much better option in this case.