Is what happened to me regarding the extra abaya and the shoe I took from the Grand Mosque considered among the forbidden things, and is it a reason for my lack of success in my life matters?

You must exert effort to return the extra abaya or its price to the shop owner. If you are unable to do so, then give it or its price in charity on his behalf. If you find him later, give him the choice between approving the charity or returning its price to him.

As for the shoes taken from the entrance of the Haram, it is most likely a minor lost item (luqatah) that is permissible to use, unless they are of significant value or were taken from a private place. In this case, they or their price must be given in charity due to the impossibility of returning them to their owner.