Three Sport Athletes

Only if you get injured in one of the other two or it detracts from your training in baseball to the extent that you don't develop or play as well.

Yes, it will be detrimental.

How much depends on how disciplined you are.  Also how much you are willing to sacrifice.  Socially, friends etc.  disciplined enough to hit off the tee or at the cages after football practice?  Can you keep your grades up?

It might be more fun to play all three.  I really don't know enough about you, your high school seasons, coaches, expectations, your goals, etc. to say for sure how much, or if you could catch up on baseball later.  I think only you know for sure.  Give it some thought.  

Agree with Go44 & Nuke 83...wholeheartedly!

The other important factor(s) is the overlap of sport schedules...you will likely miss some games/practices while one sport is wrapping up their season...which Coaches don't "cotton to" too well. 

As I recall, you are 5' 8" & 140 #. IMO, a half-way decent "hit" in football would airmail you into the middle of West Texas! Not worth the risk, if baseball is indeed your passion...

Are you more interested in contributing to "a team"...or self fullfillment? 

In the league that I play in, there should be no overlap in terms of seasons. I would most likely be on the Jv for basketball and possibly the varsity for football. I could contribute to both teams.

It depends on the player and how athletic they are.  There was a young man on my son's high school team this past season that played basketball, football and baseball.  He also earned scholarships or offers to play all three in college.  Granted they were not all Division I offers but still a pretty impressive feat.

Do you think you’ll play any in college?

If not, have fun and enjoy high school to the fullest!

If so, still have fun but make sure that you continue to develop in your main sport.