[My question is, why is it okay to pray for a parking space and not okay to pray for a win (since I don’t care for football and don’t mind a long walk both seem pretty petty.]
While “may the best team win”, or “please help me and my mates to play well and be safe”, would generally be a healthier desire, a desire for the worse team to win might at times be justified, eg a madman might be going to release COVID25 unless an unseeded team miraculously beats the number 1 team. My needs might out way my neighbour’s needs for the last remaining parking slot in a busy city. But often such things are as you say, petty, but children often ask and get petty things.
Yet prayer is not magic, and prayer doesn’t work though it can influence. God can work, and our requests can influence how he works. As C S Lewis put it, God considers our requests.
Some requests will definitely be in line with our God-given mission, even as Jesus’ requests were (and always answered—“if it be your will” is no exception). Hence the promise that praying in line with Jesus’ will (in his
name) would get the same results as if Jesus prayed them. But a mere tacking on of “in Jesus’ name” won’t work any magic (Ac.19:13), and mere selfishness doesn’t get far (Jas.4:3).
Above and beyond, our father is open to hearing from us, so we’re encouraged to put into words what we’d like from him (Php.4:6). These will be considered but not always seconded by God.
And while for simple I’ve used the term prayer, as
request, there are many types of prayer, such as chat, complaint, praise, adoration, etc. You might enjoy
https://archive.org/details/prayers-gone-global-exploring-biblical-prayer/mode/1up.