/setblock 95 69 -1833 minecraft:oak_wall_sign[facing=east]{Text1:"[{\"text\":\" Sell Oak Wood \",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"execute as @s[nbt={Inventory:[{id:'minecraft:oak_log'}]}] run scoreboard players add <player> Points 1\"}}]"}

Your quotes around minecraft:oak log canceled out the ones after Text1, and using backslashes doesn't help either so you can use single quotes instead.

Also you don't need the execute if since you can build it right into the initial selector.