Help with international B&P'ing or trading please

[Trippin Hillbilly]

Hey guys/gals

This might be a dumb question but hey, gotta ask..
I wanna get into trading or at least get started but as you can see, im in london which makes it kinda hard since most of you guys are in the US..

I remember I read something about tips for international traders but I cant find it anymore.
I know this sounds vague but i dont think the uk post offices would know what the postage costs would be back to london from the US, does that make sense?
If anyone has any suggestions then please let me know..

Muchos gracias