In most cases, to recover your wallet you will need a recent archive file that has been exported from an archive node.
Still have access to your wallet?
If you still have access to your wallet (i.e. your seed phrase is correct) but it is not in sync with the latest block, you should perform a chain re-sync. This will put you on the correct chain with your latest wallet balance.
The most common reason for a chain re-sync is if your node has been offline for too long and it cannot catch up with the chain automatically.
Lost access to your wallet or your device?
If you have lost access to your node completely, you can restore a backup that you have previously taken to a new or existing device. If you have a recent backup (within 1-2 weeks for Android or up to 4-6 weeks on desktop/server), then this is the ideal option.
Alternatively, you can import your seed phrase if you do not have a backup. Your wallet will be recovered from the 24 word seed phrase you provide. This should only be used as a last resort.
All the above processes can be found in the Security MiniDapp.