Baseball players do use the on-deck circle and they use it to prepare for their at-bat. Some players just stand there and do nothing, but this is not the purpose.
Although each sanctioning body has their on rules you are typically limited to 2 bats when warming up in the on deck circle.
A baseball glove
baseball players need a ball, bat , socks, shoes, glove
MLB players only use wooden bats. College level players use metal.
most baseball players use bamboo. maple and hickory is used alot too. but ash is the cheapest.
Baseball players use pine tar for more accurate grip when they are batting.
Little League ball players use Wilson baseballs.
A few of the brands of baseball gloves used by Major League Baseball players use include Rawlings, Mizuno, and Wilson which are the largest glove manufacturers.