That's a pretty good coastline for your first time! I like how it is boldly earth-based, but with its own interesting alterations. Some things to think about as you place terrain;
1 - Russia is off the map to the east. Is this intentional?
2 - You can place mountains, rivers, etc much as they are in the real world. If you move the mountains, then the rivers, deserts, etc. will change accordingly.
3 - Use lots of forests. Heavily populated areas (like china, europe, and america) are deforested as those populations grow. So, an early society (esp a fantasy one) will not have done that so much as in we have.
4 - Continental vs Maritime climates; anywhere in the middle of a big climate has colder winters and warmer summers than one on the coast. This is why London is more temperate than russia or canada at the same latitude.
5 - Glaciation - the glaciers coming down in the last ice age carved huge valleys that are now filled with rivers & fertile fields.
6 - If you want to make major deviations from earth normal, I suggest you decide where your local campaign is going to start. Then, you can decide what all needs to be there, place it, and build out from there. You could zoom in on a region, fill it out, and then depict those same features (the large ones, anyway) on the global map. That might give you a good starting point.

All in all, you seem to have started off pretty well. Keep updating the thread as you progress, ok?