With regard to your very low cb stats, i'd advice killing chickens until 10 str. Then, kill cows until lvl20 str, atk and def, before attempting to RuneScape gold dungeoneer. This is because the monsters that lurk there will pile you.. If you are able to take them out, you'll be killed... At around twenty years of melee statistics, you shud be able to combat them with enough.
Another point.. If you're going to get combat exp, don't be in an organized group.. And if u choose to do so, ensure ur team mates are around your combat lvl (or less).. As the monsters are determined by the average lvl of the team.. For instance, if i was ur friend on the team, (lvl 91) then the monsters would be in the 30s-80s.. This means you will probably never encounter them.. And tht if they did attack, you'd quickly die... If you solo it, most monsters are around your level...
This brings us to the most important question.. If you are determined to get an 1h wep, purchase an Longsword (get the best longsword tht u can use... If you go for lvl 20 atk str, def and str according to my advice, you could use the marmo-thingy (or bathus) metal to make ur wep and armour . Bear in mind that you will have to unlock the complexity of 6 or so before you can make armour.
If you're really looking at those statistics, you wont get into an acceptable team for gwd , or anything that isn't mass. For barrows , I recommend purchasing 70 mage or the range of a black salamander. What you need to do for melee brothers is cast an ice blast, then sit diagonally towards them and hit them by using the salamander to make two hits.
Then you go behind the sarcophagus, burst again and then repeat. Kill ahrim and karil as normal. The inventory includes runes and the melee weapon (and shield if you wish) spade, 3 ish pray pots, dhide for Ahrim if not praying as well as the rest of buy osrs infernal cape your food.