Don't even try getting to the city just yet. Just like in fallout 4, you should skip the story (or do the first bit to get a hand on it) and then exclusively do side quests until you're a much higher level. At that point, if you want a bigger challenge or its just too easy, up the difficulty. Hang on to your valuables. See a challenging deathclaw but can kill it with some explosions and a few shots? Kill it with your weaker guns. Always save the bigger guns for the bigger deathclaws. When you're further in the story, go north and walk along the northern top of the map. Around there, you'll find a very good gun held by some powerful threat. The gun depends on a perk you activated/didn't early on called the wild wild wasteland perk. [b]A[/b] gun will be there, but it'll be dependant on what choice you made. If it is a gun that has rare ammo, never use it, except for when you go to the far bottom right side of the map, directly south of the legions camp. You'll find a legendary deathclaw and a piece of remnant armor (very, very good armor. It's the x01 in fo4)