I think you should have done short term trading well first. Because traders are a pretty interesting job, it helps you train discipline and better understand the market than anyone. It forces you to learn more and requires more of your individual virtues. Therefore, the short-term trade is really necessary for newbie, because later you have long-term investment, you also choose a good time to buy and to make the least loss. absolutely do not trade margin, you will only get bad results, just trade normally.
I squabble. Newbies should rarely go for short-term trading. Short-term trading means trading in span of 1 to 5 days. Prices are much volatile and do you really think, newbies might be able to find any profits in such short terms. What I personally experienced is that most of the newbie traders who are willing to go for short-term trading end up buying coins at a wrong price which would make them wait for more than they expected in order to gain some profits but this would not be what was expected by them and also they do fail to properly manage their funds in this situation.
I would suggest newbies to start investing into coins for long term. They might sell their coins if they find profits in short term but always consider you would invest for long-term in any coin you invest because being new to the markets, you could not really predict the prices accordingly.