OK here are a couple tips that hopefully will help you out.
1. Make sure when you are soloing you are not soloing anything grey. They will give you no xp. Stick to green and blue. It's a bit longer then grouping but you should be ok. Start with greens first (one only then you can try the groups if you feel you can do it) then if youre comfy with that move to blue mobs, single only.
2. Quest quest quest quest!!! I cant stress this enough! The quests are very simple to understand and easy to do. Most can bbe solod and will give you both xp and cash. Many of the quests will have you going out killing thiongs you kill anyways; you just get xtra xp at the end and cash or items. Go for even the most minor thing you can find, you will still make money and xp.
Lastly, when you do group with people, take note of how they play and if you get along with them. Add those to your friends list and you can always send them a tell if theyre on. You can hopefully make some nice friends that way.
GL