I've just downloaded bitcoin core and the whole blockchain, but it gets stuck when trying to open the wallet itself. Should it take a long time and I just have to wait, or is there a problem and a way to fix it?
I just tested it by opening a 4 year old wallet: Bitcoin Core starts, and shows a window with "Rescanning..." at the bottom. It's now going through hundreds of GB of blockchain on my local disk to check transactions on all addresses inside that wallet. If yours shows the same, just wait. This can take a few hours depending on your system.