For probably the most half, your pockets software program ought to care for all this. You need to solely decide how urgently you want the transaction to be confirmed and choose the feerate, the pockets would care for the remainder. The 88 you point out would doubtless consult with a feerate of 88 sats/vbyte right here, though that appears like a gross overestimate on the present market situations.
If you wish to manually construct a transaction, you’ll want to know a bit extra.
Earlier than you construct a bitcoin transaction, you realize which transaction outputs you’re aiming to create. The recipients addresses inform you how a lot knowledge it’s going to take to specify every output within the transaction. The transaction header can be largely fixed measurement, it is 10 bytes for non-segwit transactions and 42 weight items for segwit transactions.
The enter aspect is a little more sophisticated, as you normally have no idea upfront what number of inputs it’s going to take to fund your transaction. Your pockets can also be capable to spend Unspent Transaction Outputs (UTXOs) of varied output sorts which take totally different quantities of information to incorporate in a transaction.
So, you will both want to select the inputs first, then decide their measurement and calculate the charges, or you are able to do each in live performance, by calculating the associated fee for every enter and deducting in from the UTXO’s values earlier than contemplating them for inclusion.
The precise sizes for some standard output sorts may be seen on this desk: 
