You have to talk to the guy who sells them and then he will recharge it for you but it will cost tokens.
you could try fist of guthix. when you get enough tokens buy the rune berseker shield or something similar or better it sells for 50k but it has to run out of charge the man who owns the token shop where you buy the rewards, you could ask him to empty the charges in the shield
You will need to charge the shield up before the spikes become visible.
saradomin shield
Antidragon shield
the second floor of runescape has a npc walking around with it talk to him he will hand you one.
Their are shield shops all over Runescape. You should be more specific.In North Falador near the fountain.
An elemental shield is 845 gp.
grand exchange
no
The best shield for a non member in stat wise is the Rune Kite shield however if you want rarity the You can go for one with a trim in the colour of the runescape gods.
If it is the shield that your gang had you can simply go back and get it. But if it was the other gangs shield you need to get someone to get you it.
You can buy one from the Grand Exchange or you can buy an Addy Square shield from the shield shop in Falador