Got this off Amazon:
https://smile.amazon.com/gp/product/B07BLNWZHS/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&th=1

I get all the major networks along with pretty much every other local channel. I have to put it in my window though or else it doesn't work as well, so take that in mind. Might need an extender cord so you can put it in the best spot.
An other option is YouTubeTV or Hulu Live. Both have the major local networks.

....Rabbitears link here: https://www.rabbitears.info/s/1012533

Also, I will be on the 7th floor of an apartment building with a private balcony ....

You have good strong signals and since you're up high at 70 feet in that apartment building you probably have a very good chance of getting good results with a simple $10 rabbit ear antenna (the type with the long telescopic rods, the longer the better).

Get one from a local store like Walmart where you can easily return it for refund if it doesn't work well. Look for something that looks essentially just like one of these 3 :

........

$10 @Walmart, an ONN brand rabbit ear style tv antenna with VHF dipoles plus a separate UHF loop element, Non-Amplified

https://www.walmart.com/ip/onn-Indoor-Easy-Adjust-HDTV-Antenna-with-VHF-Dipoles-and-20-Mile-Reception-Range/867389914?athcpid=

• Attached coaxial cable length = 4.26 ft (1.3 meters)
• 2 Dipoles 6.2 inches (15.7 cm (retracted) 15.5 inches (39.3 cm) (extended)
• Brand onn, Manufacturer Part Number 100008783

........

@Amazon, an $8 rabbit ear style antenna:

ANTAN DVB-T655VA Indoor UHF/VHF tv antenna with 10 foot coax cable, Non-Amplified

https://www.amazon.com/dp/B085S4LGMS/ref=vp_m_pb_TIER3_cmlr_lp_B07D4YW5HR_pd?_encoding=UTF8&pd_rd_i=B085S4LGMS&pd_rd_w=MfTzb&pf_rd_p=

......

$12 @Amazon, a Philips brand rabbit ear antenna, Non-Amplified, model ‎SDV8201B/27

https://www.amazon.com/Circular-Tabletop-Compatible-SDV8201B-27/dp/B07BLNWZHS/ref

.........

And as already has been mentioned here, do not resort to getting any amplifiers unless you're absolutely sure you need one. Amplifiers can easily overload with strong signals and often are not needed anyway.

A totally passive passive antenna system with no Active Electronics is always the best way to go whenever possible.

Good luck!