First of all I want to say that if you are new at trading and don't know much about analysis then my suggestion will be for you don't go for short term trading and also don't fall in future trading. You have already mention that you have faced loss on future trading. You have also mention that you don't wanna invest on alternative coins I think that's a good idea. When investing in alt coins there will be always a question on the secureness.
In this case you can invest on Bitcoin but there will be also the risk will remain if you wanna get from a passive profit from this fund. Because in term of Bitcoin if you wanna do short term trading then you must have enough knowledge about technical analysis then I think you can get a good passive income without facing loss. But if you have don't know about technical analysis then I will say that put the money in Bitcoin for long term if the fund is Idle.