do let me explain my schedule before I go to describe the issue:
11AM: Car starts perfectly and no problem, Went to go pick up my girlfriend
11:30AM: Stopped At 7-11 to get something to drink
11:32AM: Walked out of 7-11 to go start my car and drive home.. my car wouldn’t start, it was turning over (just the starter) and it started but then killed itself, second time starting, it Started with no problem.
11:40AM: Pulled into my driveway and turn off then back on for 5 times and it ran and started perfectly
1:30PM: Went to go start my car and it just had a long 7-10 second starting delay, you can hear the starter engaging but would actually start up until constant holding the key in the run position, finally starts
1:45PM: picked up my friend to drop off his car 95’ SC400 at an audio shop and car started perfect
2PM: went to the mall to kill a few hours till his car was ready
3:30PM: we left the mall and the car turns over perfectly and ran good and dropped him off at home and still ran good.
1AM: went to go drop off my girlfriend and the car still starts as normal
Today: went to go start it and it did start but was a slow start with out me holding the key and then started, my dad (his whole life of experience working on cars) tells me it’s the starters but he did use to work on old cars, not so much as new cars but he said if it’s like back then, the starter will have a solenoid, I believe it’s the alternator but he says once the cars started then it will keep the car running and shouldn’t kill it and that’s his reasoning for it being the starter

 

Have the battery tested, this cold weather is tough on good batteries let alone one with a few years on it. Ive had to hold my key in the start position a little longer than usual in this cold weather and mine is garaged.
The stock alternator 05-08 are weak and problematic. The 09-10 denso is a better choice. I haven't installed mine yet, the only difference I see is the main battery post diameter is different between the two. I'll wait for some warmer temps to play with that. I think you should take your Dads advise.

 

Take it to your local autozone and have them test the charging system for free. At least you will know your battery and alt condition.

 

Since it's a work or no work problem it could be a wire problem. Sometimes you have a good connection and sometimes you don't. Check and clean the battery terminals and the ground wire. Also, the wires at the starter.

 

It apparently was the fuel pressure sensor.. I know on old fords that a fuel pressure sensor could cause a car to not crank over and apparently replacing it fixed the job