It's doable. The westside is very bike-able; Particularly, Santa Monica and Venice. You just need to be very cautious because the drivers out here don't give a fuck about cyclists. Also, bike theft is very rampant. So carry a good lock with you. Don't ride/walk around late at night. Venice is very touristy and safe during the day. But at night, it can be a little sketchy.
The Big Blue Bus
services Santa Monica, Venice, and the bordering cities. Culver City bus
and the LA Metro
can take you further out if you want to explore. We do have a rail system that can take you to various places outside of LA. Day passes are $5 and week passes are $20.
If you're desperate, you can always use a cab. But they're freakin expensive. Not really worth the money unless you need to get somewhere fast. There's also Zip Car
on the westside. But I'm not sure how that will work since you don't have a California or US drivers license.
If you have any other questions, like the best way to get from A to B, go ahead and post it. Our collective minds will help you out.