Getting into college is not difficult for homeschoolers. Many colleges like homeschoolers because of their independent study habits and individuality. A high school diploma can be obtained from a high school long distance curriculum, or it can be obtained by GED testing. We opted for the GED tests. My daughter received a certificate of high school graduation after completing the tests.
Another important aspect is ACT, or SAT testing, depending on what the college of choice will accept. It is a good idea to do this test twice, because on taking the test the first time, the student will find out what areas he, or she needs to prepare more thoroughly for. There are ACT practice, and study books which help greatly!! I would say to take the ACT in the fall of the senior year, and then again in the spring.
One thing I forgot to mention is-when the student is a high school homeschooler, he or she will be able to study independently. A parent should supply the guidelines and appropriate books and the child, in my opinion, can make up their schedule, and do the work at their pace. At this age, my daughter was also working part time, and participating in community theater performances.