Where to find data on BTC transactions?

1M Ago
"The whales are buying" - this is sometimes circulated in the crypto community. Where can I check to confirm this? ​ More specifically, I would like to get the answers to questions such as: 1/ Are the large (non exchange) wallets accumulating bitcoin or selling? 2/ The wallets that are selling, how long have they held it before selling? 3/ The wallets that are selling, when did they sell/buy in the past? ​ This should all be publicly available, right? If noone is offering this service then... fine, I'll do it myself. ​ Where is the place to go to get started with the bitcoin API? Or, in general, how to go about programming something that would do these kind of analyses of the blockchain?