stop by a Auto Zone or similar place, and have them check the battery. The will put a "load" on the battery to see if it is up to specs. There are a lot of other things down the line that can cause this, but this is the easiest to test. They do this service for free. They will look at your battery connections as well. Best place to start....

Hard to start could relate to fuel, to electrical, many things, but you have to start somewhere...