How to activate commands around a tagged entity with command blocks?

Make sure you have a scoreboard set up, you can add one using this command:

/scoreboard objectives add <objective> dummy

The first command has 2 spaces before the @a[..., it misses a = after scores, and you didn't specify what objective to add 1 to.

execute at @e[tag=GFlag] run scoreboard players add @a[scores={dropFlag1.0=0},team=Red,distance=..2] <objective> 1

The second command also doesn't specify what objective to add a point to and it executes as the command block and not as any player, it only uses the players location. This is what it should look like:

execute as @a[team=Red,scores={dropFlag1.0=0}] at @s if entity @e[tag=GFlag,distance=..2] run scoreboard players add @a[team=Red,scores={dropFlag1.0=0}] <objective> 1

I'm not sure if objectives allow a . in their name, you can try to only use letters instead of dropFlag1.0. This is what it should look like:

You should also make sure that the dropflag1.0 scoreboard objective is equal to 0 when you run the command and make sure that it exists in the first place.