One of the reasons Ark Nova is such an amazing game is because its impossible to answer questions like these.
In the early days upgrading build was very common, but people have moved away from that.
( By taking 2 size as project bonus from first project, going hard on release project, or sea animals)
When you have none of those, and are starting with a couple of sponsor buildings you might still want to upgrade build to fill map.
Sponsors is a popular one now because there are some very strong cards that require it ( Explorer, Diversity Researched, Talented Communicator, Amazon House, Science Lab )
Also using it to break give a nice amount of money.
The special action sponsor cards are also quite good overall, so higher chance of also getting to use them well.
But its all dependant on the map, and state of the game.
Association upgrade is mostly good if you either start with partner zoos and there are 2 CP available for getting 4 of them or 2 CP for last worker.
You also need to be on a map with relative high income, or having a high income start so you can keep donating.
Doing it realy is usually only done when you need the extra CP from donating to reach the bonus on 5 of 8 CP if its a very good one
( Parter Zoo or Uni mostly as getting a free one of those gives you an extra upgrade probably)
Animals is a quite important upgrade as most late game high scoring animals require it and it's a nice source of reputation.
But when playing on research institute or with the special animal action that lets you ignore a requirement you can get away without it.
Cards is usefull in general, but more so when you are going hard on the reputation track and want to get past 9 rep.
If you started with hand size uni and have a solid 4/5 card game plan in hand for the early/mid game you can wait on this one.
( again, plenty of reasons you want it earlier for instance if you have the special sponsorship action that lets you play one for money by discarding a card)