Okay... being serious now (ooooh!!) ...
Buy an oven thermometer (in the grocery store)
Put it in the oven before you turn it on... then check the temp on the dial set to the temp on the thermometer.
Sounds like the oven may not be getting hot enough.
Set the oven for 325 Degrees then check the thermometer.
If there is a difference, adjust the dial setting to compensate.
Say the temp reads 300 Degrees when the oven is supposed to be at 325. Turn the dial up 25 degrees over what you are supposed to be cooking at (350). Then check the thermometer again. Should read 325.
Remember to make this adjustment every time you bake.
Next step: Try baking something.
Most important tips:
Measure correctly. Use a round measuring cup for liquids and the oddball shaped ones for measuring dry goods (usually connected together in a group on a ring).
Always measure stuff over the sink, not the bowl you are putting the measured ingredients into. ('till you get really good) (I made Deviled eggs about 10 times and always measured the vinegar over the bowl. Wangiest Deviled eggs ever! So I made them correctly twice, but now we like the wangy eggs better... bite into a lemon puckerface wangy!)
Check the oven temp.
Follow the directions.