Any tips for starting Track??

Okay so I can't really 'prepare' very well because track practice is in 4 days. Well I played soccer for 7 years and over that my coaches have always told me I could be the fastest player if I would just be confident and put all my effort into it without questioning myself. I'm trying not to do that anymore, obviously, but I'm just really nervous that I won't do well. At my school, they choose which category you'd be best in, but I will most likely end up in Short distance because I've always been good at sprinting. So any fellow short distance runners have any tips?

Like, what type of work out schedule do get into, exercises that would help, how to practice it at home, etc. ?

Also, if you were ever nervous about starting track, how to push yourself further? I struggle with pushing myself if I know I don't HAVE to do it. Like if I'm running laps and I get tired, I don't even TRY to keep going, I'm just like 'Well there's not really anyone to MAKE me run so why should I?' and immediately stop. I hate it when I do that but no matter how hard I try not to give in, I do anyways. SO any tips on how to push yourself?