@mom4bwayboy gave some great advice about the “need for speed” for your timeline. Most Musical Theatre and Acting program auditions have demanding and varied requirements. If you want to audition for MT BFA programs, ideally you will need the following material prepared by the end of the summer:
A “rep book” containing 16 and 32 bar cuts plus the full song for :
- a Golden Age uptempo and ballad
- a contemporary uptempo and ballad (around 1970-2010)
- an appropriate role from a show that has been on Broadway in the last five years
- a comedic song
- a pop/rock/country song
- a few BM programs also require an "Art Song" from the typical Vocal Performance audition repertoire
This list is from this post from an MT college faculty member: http://talk.collegeconfidential.com/discussion/comment/18817863#Comment_18817863
The songs that you pick should show off your vocal range and “acting the song” abilities.
You will also need at least two contrasting monologues from published plays (not musicals) that are age appropriate, in both one minute and two minute cuts. Depending on the programs that you apply to, some may have additional and specific monologue requirements such as a classic monologue from the Shakespearean era. The audition panels will typically be looking for you to demonstrate at least some command of Shurtleff’s “12 Guideposts” (from the seminal book on auditioning, “Audition” by Michael Shurtleff):
http://www.crystalcreekmedia.com/12-guideposts-to-a-compelling-audition
Since you don’t have much experience on stage, I would strongly recommend reading the “On Acting” series of articles that Jon Jory published in Dramatics magazine - you can find them in this list from the Educational Theatre Association (Thespians) website:
https://www.schooltheatre.org/communities/community-home/librarydocuments/viewdocument?DocumentKey=aa22bf79-4eea-4db8-89db-511532985e67
Here is a great post from the former head of the Theatre Department at Otterbein on what college audition panels are looking for:
http://talk.collegeconfidential.com/otterbein-university-mt/1035287-audition-advice.html
Many programs include a dance call in their auditions which will typically consists of:
- Basic Ballet Positions
- Basic Jazz Technique including "across the floor" combinations
You don’t have to be an accomplished dancer, but you should be familiar with the basic positions and techniques for Ballet and Jazz in order to not be completely lost. Taking some dance classes ASAP will really help you get ready. If you cannot manage to attend dance classes, at least study some youtube videos on basic Ballet and Jazz techniques and see if you can find a friend with lots of dance training to help you practice basic technique and combinations.
Selecting and preparing all this material and getting some dance training done is a time-consuming process for most applicants. Many who want to audition for competitive programs begin working on it by at least the Spring Semester of their Junior Year in high school to keep from being totally swamped during their Senior Year in High School.
As mom4bwayboy noted, in order to secure audition slots for the most competitive programs, you will need to submit applications as early in the Fall semester as possible - the audition slots for top programs tend to fill up as early as October. Many programs require prescreen videos in varying formats: 60 second song cuts and monologues, 90 second cuts, etc. and you will want to be ready to film those early in the fall.
Combined with all the work required just for the regular college applications, this is a very demanding process, and, hence, the need to begin working on all this as soon as possible in the Junior year is a good idea.
In addition to the great recommendations in previous posts, some schools in your area that you may want to look at include:
Utah
Central Washington
Arizona
Southern Oregon
San Diego State BA Acting w/MT emphasis
U Colorado Boulder
Northern Colorado