The question you posed kind of reveals that you have little or no experience with engines.
I strongly suggest that you spend the $9 US and download the service manual here:
Daewoo Lanos service manual
You will need the manual for measurement detail and you may be able to discern from the illustrations what you can expect for damage.
Most, if not all, of the valves are likely damaged, the valve guides could be affected, stem seals should always be replaced if the head has to come apart (it does), on higher-distance-used engines, I recommend measuring valve springs (you will need a micrometer and precision caliper on hand at the minimum), you may find pistons cracked at the top, bent connecting rods, damaged rod bearing inserts, damaged camshaft, damaged crankshaft bearing inserts, a complete upper end gasket set or rebuild gasket set (will have all).
The head itself could be damaged or even cracked.
Frankly, this is not a good '1st project' for anyone and if you do have no experience, you will need days of concentration to ensure you understand what is being done at each step, and you may find tools specified that aren't in the kitchen drawer and not useful for any other purpose or vehicle.
If you have a 2nd vehicle, this kind of DIY is great fun and will give you insight into the workings of an internal combustion engine.
If you need it daily, I don't recommend trying it at all.