1st post!
note always wear eye protection when working with a battery!
Could be a lot of things causing no start but since you own a 08 the battery is 3 years old not 2. IIRC the battery group is a 24 or 24f which is cheap to buy since it has been used in many cars over the years, avg price is going to be about $59.00 to replace.
Things to check. Check terminals for corrosion and clean using 50 50 mix of water and baking soda. Wash with clean water then scrub battery term and cable ends till all clean. Next thing to check is if there is the fluid above all the plates if so check the gravity of the acid in each cell and if all cells are full. If they are all full you need a battery hydrometer to see if all cells are at a full charge which should be between 1200 and 1175 specific gravity and acid covers all the plates. If there is lets say 50 points or more difference between any 2 cells replace the battery. If all cells are down recharge or below plates refill with water and recharge battery on a slow charger, 6 to 10 amps for about 24 hours. Recheck with hydrometer and make sure all are between 1200 and 1175 if all are up you need to load the battery some how ie a carbon pile load tester is best or you can try to crank motor to simulate the load test.
PS if your are using the starter to try to load battery don't just keep trying to crank it if car starts or you will tear up the starter! A carbon pile load tester with a volt meter is best.
Load test for about 15 sec and look into cells if any of the cells start to boil the cell is shorted and battery is bad. You might have to do this a couple times to get a bad battery to break down (boils) so load for 15 sec and let it cool down for 15 sec, repeat a few times. If voltage drops below 10 volts while loading battery and won't come back to above 12 to 12.5 volts after a few loads battery is most likely bad and needs to be replaced.
If battery pass's this test but still won't crank over most likely starter is bad or going bad. You also need to look at cable connections at solenoid on starter and is clean.
If car starts you will want to check alternator. Once car starts use volt meter to see what voltage is while car is started. It should run about 13.5 to 14 volts. If below 13.5 most likely alternator may be the cause or blown fuse. If above14.5 volts most likely regulator is going bad inside alternator.
Note you can take car to most auto parts stores to get a free test of all above but most have no clue what they are doing so tell them what I just typed and make sure they do what I just typed or you'll get the run around and will be buying parts you don't need. You might look in the phone book for a starter/alternator rebuilding shop to test they would be your best bet to solve your problem the best and fastest. Even some of the best auto mechanics have no clue what they are doing when it comes to starting/battery/charging problems that's why it may be your best bet to find a rebuilder.