I have a type C multiple-entry visa for Latvia from the German consulate and have R/LV written below the remarks of my business visa. The sticker says "SCHENGENER STAATEN".
This is my first Schengen visa and I want to know that can I land in any Schengen state to start my trip? or do I have to land first in Latvia ?
Secondly is there any restriction on me traveling to other Schengen states as I got a 30 days visa.
Your visa is good for the entire Schengen area, and you can enter through whichever external border point that suits your plans.
In order to avoid suspicions that you lied about your plans in the visa application, it is strongly recommended that the trip that is the first use of your visa should have a main destination that matches your application. But you're free to transit through other Schengen states on your way to or from that main destination, or to combine it with incidental minor tourism in other Schengen states.
Once that first trip is completed, you generally have the run of the entire Schengen area for subsequent visits, as long as they're all before the visa's expiration date and you don't exceed the total number of days-in-the-area indicated as duration of stay.
Rin the remark means that visa has been issued by representation.LVis the country code for Latvia. This means that as Latvia does not have an embassy in your country, the Schengen visa has been issued by another member state (Germany) on its behalf. Full list of countries where Latvia is represented by other member states is here. There are no restrictions on your visa except that it is valid for a stay of 30 days.