I would like to know if i could join two or more bounty campaigns or signature campaigns?
Firstly, there is very scarce campaigns that accept newbies as their campaigns' supporters. You should try a little bit to rank up to Junior member rank to join campaigns. Requirements for Junior member rank is available there:
In addition to activity, everyone now has a merit score, and you need both a certain activity level and a certain merit score in order to reach higher member ranks. The required scores are:
| Rank | Required activity | Required merit |
| Brand new | 0 | 0 |
| Newbie | 1 | 0 |
| Jr Member | 30 | 0 |
| Member | 60 | 10 |
| Full Member | 120 | 100 |
| Sr. Member | 240 | 250 |
| Hero Member | 480 | 500 |
| Legendary | Random in the range 775-1030 | 1000 |
That means you need more activity-counts to rank up to Junior Member. Aditionally, to move up to higher levels than Jr. Mem, you will need both activity-counts and merit points. Please visit and read the above topic for more details
Secondly, you can join two campaigns at the same week, but I don't recommend you to do this. There are two reasons:
1. You should be honestly with campaigns you support and earn money from them. Don't try to cheat like this, it's not good behaviour, honestly.
2. If you try cheating both campaigns, the probability to succeed will totally depend on the way managers of campaigns managed their campaigns. If they manage strictly, you can certainly not cheat them that way.
I also give you link to very useful topic which created by Lauda about tutorials to get first
BTC for new-comers in the bitcointalk forum.
https://bitcointalk.org/index.php?topic=1629118.0