First off, think about how much you like camping. How often will you do it realistically? Will you stay camping more than you do now? Do you think you'll be backpacking and camping? I.E. hiking to a campsite, stay the night and then hike several miles to another campsite.
If you won't be camping very often, say 2 or 3 weekends a year and you normally will be car camping or only hiking a couple miles to camp, then you don't need the lightest and best gear.
Take this tent - great deal, roomy and should last a casual camper for years and years. Coleman Hooligan 2-Person Tent,Orange https://www.amazon.com/dp/B0016HMBN0/ref=cm_sw_r_cp_apa_kUtEybSZA8DB4
Do you shop at Amazon? Teton Sports makes some excellent bang-for-you-buck backpacks.
Use the BULK your money on good sleeping pads and sleeping bags. Sleeping well will make a world of a difference in your enjoyment. There are a number of good options,I would recommend going to a store like REI where you can really touch and feel the gear, plus they have a great return policy so you can try out a sleeping bag and pad without being stuck with it.
IMO, 10X9 is way too big for Coachella considering the close quarters.
Try a 2 or 3 person Coleman Hooligan. You'll conserve space for your common area and save some money as well:
Coleman Hooligan 2 on sale for $50. Or splurge and get the 3 man, I have the 3 man and it has plenty of room. Its heavy but should work. The vestibule is nice and it offers great wind and rain protection.
Your remaining budget of $300 can go towards any other gear/creature comforts you may want: Camp chairs, a cooler, sleeping bags, sleeping pads, sexual lubricant, etc.
Backpacking - Coleman Hooligan 2-Person Tent,Orange https://www.amazon.com/dp/B0016HMBN0/ref=cm_sw_r_cp_apa_PYiXybA2KXPP8
I had good luck with this tent until I did finally upgrade. For the price you will get your money's worth. Less than $50.
Coleman Hooligan(TM) 2-Person Tent https://www.amazon.com/dp/B0016HMBN0/ref=cm_sw_r_other_awd_PoNexbC0WR5NY
Got this tent three years ago and it's amazing for Coachella Coleman Hooligan(TM) 2-Person Tent
https://www.amazon.com/dp/B0016HMBN0/ref=cm_sw_r_awd_8uWhvb1ZXQMDS https://www.amazon.com/dp/B0016HMBN0/ref=cm_sw_r_awd_8uWhvb1ZXQMDS
Also, if you're gonna run your car to charge phones or whatever, Id recommend some ducting to reroute your car exhaust to the front so you don't blast your / your neighbors site