I like the Isis CB5 - it's a nice weapon, and a great way to start skilling blp rifle.
True it's limited so you can't repair it, but it's still very economical to use, almost the same as an opalo, and it lasts a long time (decay is very low).
The only drawback is that there is no good amp for it, comparable to the A10X laser amp series.
If you want to carry on down the blp route, stick with it, but remember the opalo which is the equivalent laser rifle available from the TT is not limited, which removes the problem of keep buying new ones. It all depends on which you prefer to skill - laser or blp.
Assuming you plan to start with hunting (and it's a good place to start, since it's useful to be able to defend yourself when roaming the countryside, and gives useful skills for other professions too), and you want to carry on with blp skilling, I would suggest you keep going with your CB5, killing small mobs, at least until you have maxed the hit and damage for it. (ie until the weapon stats say 'not any more' for skill bonus)
In general, killing small mobs probably gives you more skills than big ones, because you seem to get a small bonus for each kill.
Also, I would suggest setting yourself some small targets. Do you have all the TPs on eudoria? If not, you could set yourself the target of getting some more of these. Many can be achieved alone, without someone running you, and it's all the more of an achievement when you get there on your own.
Having all the TPs is really useful, unless you plan to spend the rest of your life in PA, since it's a real pain when you are invited on a team hunt, and they say 'meet at echidna' and you don't have the TP
Other than that, I would say, explore, try out killing different mobs to see what you can handle. Do you have any thoughts yet about which direction you might want to go? Any profession that you think you really want to do?
You're right about hunting not being great on your ped card - you almost certainly won't profit at the start unless you are very lucky.
You can help offset this, by hunting mobs that tend to yield higher markup loot. The higher the markup, the less you will lose on each hunt.
Sabakumas are good because they tend to yield lots of paint.
If you can manage them, you could also look at merps, caudatergus and fouls, but you may find your own preferences.
On the other hand, snables are nice for skilling as well.
You may find you can kill smaller mobs without armour at all - if so, take the armour off. Why waste the decay? You shouldn't need any armour to kill young snables or sabas.
If you spend your peds wisely, and hunt economically, you can stretch your money that little bit further.