Unconfirmed transaction: the status is "0 / unacknowledged, not in memory pool " I started a transaction with bitcoin-0.21.0-win64, a Windows client. It may be that the fee is set too low, which leads to the unsuccessful transaction. What should I do in the future? What do I need to do? How to implement the specific operation steps? Below is the transaction details, please help! Thank you very much！
Status: 0 / unacknowledged, not in memory pool
Date: 2021 / 3 / 8 12:31
To: coin an 1kgsxf7krv1ab99tex1wjm643tsilczbg6
Expenditure: - 0.05193365 BTC
Transaction fee: - 0.00120000 BTC
Net amount: - 0.05313365 BTC
Transaction ID: aceea84e8a72b24654cba7b1d042561d8a9d36f7828855b52012de8a5a0b9c12
Total transaction size: 11767 bytes
Transaction Virtual Size: 11767 bytes
Output index: 0
The transaction you made is quite large, so also if the fee you paid is not low in absolute term, it is in relation to the space taken on blockchain.
0.00120000 / 11767 = 0.00000010

you have paid 10 sat/vByte that was borderline to be included in a block in the days you should have broadcast the transaction.
As you can check here:
https://jochen-hoenicke.de/queue/#BTC,3m,count
there are some transaction with a fee rate similar to your that have been verified (note that it generally takes 14 days for the transaction to be removed from the mempool if not confirmed), so i'm not 100% sure the fee rate is the reason because your transaction has not been verified, maybe there is another reason (eg. when you made your transaction your client is not fully synchronized and you close bitcoin-core before the transaction was actually submitted).

What should I do in the future?

Be sure that your client is synchronized or at least check on a blockexplorer that your transaction just submitted is in mempool (although not yet confirmed).
Enable Replace By Fee so if the fee you set turn out to be too low you can raise it later.
You can also use the bitcoin-core fee estimation choosing recommended transaction fee and setting a confirmation target no longer than a few hours.
Remember to check that the transaction has been verified before 14 days have passed since its submission.