$700 is a tough price point.

Save up $500 more and your options open up a ton. For your first bike I (cautiously) recommend a new bike shop bike. Best value is clearance, esp. new old stock.

Performance and REI have special sales a few times a year with steep discounts, and you can test ride if these stores are in your area.

Save up a few months more and get a really nice bike. $1200 will get a bike with tiagra 10 speed, much nicer than what you'll likely find at $700.