First off I would like to start by saying thank you in advance to anyone that is able to help. This is going to be a long post. I just recently traded my 95 f150 for a 95 mustang 3.8l v6. Eagle cam, eagle pistons, ported and polished heads, headers and 80,000 miles. The car is a 5 speed. Anyhow, few things I want to fix before upgrading performance. While at a stop, car running, I try shifting into first but the gear grinds unless I shift really slow, or I shift into first while almost stopped but not completely. Not sure what this is never had any issues with previous manual transmissions. Second, while taking a gradual right turn I can feel a "knock" but not when I turn left. And last the car is very squeaky, now I know this has to do with suspension but I am a truck guy, new to cars. Not sure what to look at first to stop the squeaky suspension. Any help is appreciated, thanks guys!

 

For the trans, sounds like a synchro failure. Take the time to watch the youtube video in the link below and you will understand what is happening inside your trans (also could be a clutch release issue).
As for the suspension, you gotta get the front end off the ground and check tie rods, ball joints, struts, wheel bearings, and lower control arms (squeaky bushings).

 

Thank you for the reply, had a feeling it was some kind of bushing causing the squeaking, and I think its a ball joint issue. Will try to get the front end off the ground tomorrow and check it out! Have a good day!