First portaits tips?

[jon.t.]

So yesterday, my mom told me that she'd buy buy me some film if I took a few portraits of my brother, by the end of the weekend. She said she'd rather have them outside, near this tree in my front yard (she likes the pink/purple colored leaves). I've never really done any "portraits" before besides some extreme night shots, so I have a few questions.
My set-up consists of:
50mm 1.8
Sigma 70-300 4-5.6
18-55
Vivitar 3500
Sunpak 433
Umbrella (shoot through and reflective)
DIY ringlight
Wireless Slaves
Misc. items
Do I shoot towards my house, or the street?
Which lens should I use? I was thinking the 50 1.8 but it's only manual focus.
Should I even bother with the lights? Maybe I can just use the umbrella for fill flash?
Sorry to sound stupid, I just don't usually do pictures like this, I do mostly sports.

Thanks
-Jon

[breathless]

You can produce nice portrait images with your camera and any one of your lenses using available light, and you can produce nice portrait images using all of your equipment. If you're not very familiar with the proper use of your flash equipment, AND you must get images this weekend with little time to practice; KISS(Keep It Simple Silly.)

If you choose to use available light, try to situate your bro in shade. Use relatively wide apertures to separate your bro from the background and bring attention to your bro. Get closeups, 3/4, and full lengths. Try multiple angles and perspectives. Continually exchange conversation to get various expressions and movements which depict his uniqueness. Have him engage the camera and looking away. Then trick it all out in post. Suddenly, you're mom's favorite.

[jon.t.]

You can produce nice portrait images with your camera and any one of your lenses using available light, and you can produce nice portrait images using all of your equipment. If you're not very familiar with the proper use of your flash equipment, AND you must get images this weekend with little time to practice; KISS(Keep It Simple Silly.)

If you choose to use available light, try to situate your bro in shade. Use relatively wide apertures to separate your bro from the background and bring attention to your bro. Get closeups, 3/4, and full lengths. Try multiple angles and perspectives. Continually exchange conversation to get various expressions and movements which depict his uniqueness. Have him engage the camera and looking away. Then trick it all out in post. Suddenly, you're mom's favorite.
Hahaha thanks, but If I take good enough pictures, wont my brother be the favorite :~(