Need advice on losing weight/toning arms

You got this!

Since you don't have too much weight to lose, set your calorie target to lose .5 pounds per week and start a 3x/ week strength training program that involves heavy compound lifts like squats, deadlifts, overhead press, bench press, and rows. Pushups aren't a bad idea- just make sure that you're moving up to a more difficult variation whenever possible (like going from pushups on your knees to military-style pushups). There are a lot of great programs out there that I'm sure will be mentioned in this thread such as Starting Strength, Stronglifts 5x5, and New Rules of Lifting. These programs have groups on here, if you want to look into them.

In my experience, the only thing that high reps with a low weight accomplished was endurance. I went from being able to easily do 20 bicep curls to easily doing 30 bicep curls, but no real visible difference in my arms. A higher weight that you can ONLY DO very few reps of will train strength and preserve your muscle mass while you're eating in a deficit and/or doing cardio. Heavy lifting is very much a relative term- I might struggle to get 5 reps on a weight that you could lift all day. Start with a weight that you can lift 5 times with good form, but couldn't do many more reps than that without sacrificing form.

Challenge yourself, try to add more weight every session, and do research on proper form to prevent injuries. It's common to gain a few pounds of 'water weight' the first couple of months on a lifting program, and many people experience a slight swelling or 'poofiness' in their muscles as a result of their bodies healing from the new exercises. Don't let it discourage you- it does go away, and you'll love the way you look.

Best of luck!