if someone is very reserved and is not social and he befriends some one for his personal benefit and help, is he doing shirk? like if one befriends a person just to get conveyance facility or any other type of help etc

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

It is permissible for someone to befriend someone else for the purpose of getting a permissible benefit from him and this matter in itself is not forbidden, let alone being Shirk [associating partners to Allaah]

Indeed, the scholars have stated that seeking the help of a creature in matters which he is capable of is not considered Shirk at all. Allaah Says about Moosa (Moses) (what means): {And the one from his faction called for help to him against the one from his enemy, so Moses struck him and [unintentionally] killed him.} [Quran 28:15]

Shirk means that a Muslim associates a partner with Allaah when worshipping Him, and so he devotes to him some acts of worship which he is not permitted to devote except to Allaah. Ibn Mas’ood said: “I said: O Prophet of Allaah, what is the greatest sin?” Thereupon, the Prophet said: ''It is to associate partners with Allaah while it is He Who has created you.” [Al-Bukhari and Muslim]

Finally, it should be mentioned that a Muslim should not befriend another Muslim just for worldly benefits; rather, this should be in order to achieve the meanings of brotherhood that are highly emphasized in the Sharee’ah. Indeed, a Muslim would gain from such brotherhood the benefits of this worldly life as well as those of the Hereafter.

Allaah Knows best.