In the Carnot Cycle how come we can take up enrgy to deposit in the second sink if the process is isothermal? What puzzles me is that if the process is isothermal in nature how come we have energy left to deposit in the second sink?
PS- this is my first year in high school and the first time i am studying thermodynamics
 A: The smartypants answer is "Slowly" after which you look around in search of your rimshot.

To take the question seriously we have to deal the the notion of a quasi-static process. You are presumably objecting because heat transfer requires a difference in temperature and 'isothermal' seems to bar that. Right? Good.
So let's design something that is almost isothermal and can transfer energy. We expand than therefore cool the system just a tiny bit, say so that the temperature drops by $\delta T$ and then stand around twiddling our thumbs while energy passes from the reservoir to the system very, very slowly because the temperature difference is very small. Then we do it again. And again, and again until we reach the desired endpoint of this stage of the cycle.
We can, in principle at least, make $\delta T$ as small as we desire and so this notion gets us as close to a isothermal energy transfer as we have patience for. And this keep the combined system (reservoir plus working system) as close to equilibrium as we care to achieve while still transferring energy. (This is why I wanted to talk about quasi-static processes, because to keep the temperature fluctuations down the two parts have to be very nearly in equilibrium, and that means that things are going to happen slowly.)
A similar argument applies to offloading heat from the system to the cold reservoir, only you compress and heat the system enough for the (again, very, very slow) transfer to happen.

Practical systems (which only approximate the ideal system) don't generally use discrete cycles of expand-then-transfer-in-order-to-warm-again, but instead maintain the system a little below the reservoir temperature during the whole cycle. That is a marker for disequilibrium but the effect it has on the whole cycle is pretty modest.
Either way the key is that you are continuously adjusting the system so that it's temperature remains constant even as it's internal energy rises (or falls in the cooling stage) due to the flux of heat from (to in the cooling stage) the reservoir.
