Hi Shobos, and welcome to the forum. You ask a lot, but give us little to go on. Generally, I think you've got some pretty common stamps there, and some look to be in bad shape. But your image isn't very good, I'm afraid, so it's hard to tell what we're really looking at with any certainty.
May I suggest you scan or photograph some individual stamps and show them to us as larger images. Someone here may be able to tell you something.
Conversely, if you are new to stamps and you live near a major centre with a good library, chances are they will have a collection of stamp catalogues. You could probably take them home and do some of your own research.
Also I'd suggest taking some of them out, carefully, using tongs if you have them - try not to handle the stamps with your fingers if you can help it - and inspect the back. Latvia, around the time of the First World War often printed their stamps on old maps or unfinished currency. Not necessary valuable, but certainly interesting.
I'd be willing to bet that the first Latvian stamp in the third row is printed on currency. I have one just like it.
And here it is, front and back...

