According to this article:
The kit man takes three shirts per player to each game – one per half,
plus a spare for emergencies. Afterwards, he collects and launders
them, ready for next week. For big games, the club permits the players
to swap or keep their shirts, but that is agreed beforehand and the
players are fined if they do it when they’re not allowed.
But I imagine this depends on the player, club, country and meaning of the game.
Regarding boots, Chris Smalling of Manchester United offers some insight here:
In general most players wear a pair for training and then a different
pair for matches. You'll start off wearing them in training to break
them in and then when you feel they're ready you'll put them on for