Problems with Reverse
 

I have a 2005 Hyundai Elantra GLS 5 speed manual I got a week ago and the car runs and drives wonderfully, but when I try to put it in Reverse it sometimes struggles to go into reverse, sometimes it won't slide in to the reverse slot, sometimes it'll act like it's in 4th gear and drives forward, I'm begining to think that it could be in the shifter section of the transmission because once it goes into reverse it will stay in gear and won't try to disengage, could someone please help me figure out the issue I am having
if it helps narrow it down the car does have 218,749 miles but the car runs and drives great, although the shifter dose seem like it is sloppy, could it possibly be something worn out in the shifter section of the transmission? Cause it will take every gear without a problem and once reverse engages it's just as good as the rest of the gears

Manual transmissions usually have interlocks to prevent getting into more than one gear at a time. With wear the system may be having trouble allowing just reverse to be selected. The entire system will need to be checked for wear and inspected to determine just what is preventing the reverse from being easily selected.