Ok, you're making so newb mistakes, but they're reversable.
with the starfish:
Firstly, they don't belong in tanks less than a year old or less than 90G. This is due to the necessary fauna that is found in sand beds of established tanks. Sand Sifting Starfish are carnivores who eat all the GOOD fauna out of an established sand bed. In a 10G tank, or even a 50G tank, they can deplete a sand bed in a matter of weeks. It is amazing to really see how much these guys can eat. Once your sand bed is depleted, it is of no value to the tank. It does not help filter anything and can actual start having ill effects on your tank and become a nitrate producing factory. Yes, it is possible to feed them, I've fed my two for years. However, in a 10G tank, you will never be able to feed them enough to keep them from eating your sand bed. I have two in my 155, and I can barely feed them enough to keep them from munching down on all the good stuff in the sand. I have to reseed my sand fairly often. I'm actually getting rid of my two today because I'm tired of the work involved in keeping them.
the anemone:
Anemones are 90% water. New tanks, being very unstable are a very dangerous environment for an anemone. It's basically the same thing as if you were exposed to non-stop smog filled are for a few months, it would have an ill effect on your body. Although some people have had luck placing an anemone in a young tank (I am guilty of this myself), it is really frowned upon and we advise not to do it, especially if you're new to the saltwater hobby. Water parameters can change at the drop of a dime, especially in a new tank. The slightest bit of change in water quality can kill an anemone, and in new tanks, when there's a change, it usually isn't so slight. Small tanks added to the picture create even more of an issue. Water quality is very difficult in a small tank. Isn't this the reason you decided to start with the smaller tank? Adding a small tank size and the fact that it's new will more than likely create a slow death for the anemone. IF the anemone does die in your tank, you'll have one heck of a mess on your hands. Feeding the anemone really won't make a difference if the water quality is good and stable. Although, I do commend you for knowing that they need to be fed.
If you feel that it's time to add critters to your tank, I would add your clean up crew and a fish (or two if you plan on doing a pair of clowns). Watch water parameters for a minimum of 2 weeks and make adjustments accordingly. You may find that you need more of a clean up crew, or that it's just the right number. If I'm remembering correctly, your plan was to just do a pair of clownfish in this tank, right? You can still do a small goby or other small nano fish, especially if your plan is to EVENTUALLY get an anemone for the clowns. The clowns do NOT need one, by the way, and there is no guarantee that they'll take to it. My clowns did not have an anemone for the first 6 months that I had them and they did just fine.