I had massive issues with this wallet, it never finished syncing and ended up with no block source available.
Now I'm wondering, where can I get my bitcoins?
If you haven't deleted the wallet yet, you can extract the private keys from your Bitcoin Core wallet. Then you can import those private keys into some other wallet once you decide which wallet you'd like to use.
I imported wallet.dat to Electrum, is that it?
Edit: Wher is the option to extract the private keys? Do I have to use some kind of command in console?
Bitcoin core wallet.dat is incompatible with Electrum.
A simple guide to export private keys from Bitcoin core to Electrum.
• Launch your Bitcoin core.
• Click on 'help' in the menu bar (top right).
• Click on 'debug window'.
• select 'console' tab
• Type dumpprivkey
• This will give you private key of the Bitcoin address you entered in previous step.
• Copy this and import into Electrum.
• Wait for Electrum to sync completely.
• Now you can send Bitcoin from your address.
See https://electrum.orain.org/wiki/Frequently_Asked_Questions#Can_I_import_addresses_from_other_Bitcoin_clients.3F for importing private keys into Electrum.