Charging plug won't fit In port right

assuming you have tried another charger, If it does not fit in, there are 2 possible issues.

1) The port is dirty inside. This is much more common with phones, that hang out in the users pocket all day, however, there is a possibility. To fix this, you need an Exacto knife, a toothbrush and isopropyl. Use the Xacto knife to dig out any lint build-up, while maintaining the integrity of the pins. take great care as to not damage them. then scrub out the port with isopropyl. this is a non-conductive solution, so you may be generous with the amount applied.

2) More likely for tablets, there is physical damage in the port causing a mechanical failure. this would require a port replacement, in which you would have to source the part, and replace the port. The difficulty of the repair ranges based on model of the kindle used.