A good place to start would be to do some research and read some books, google is your friend. Good thing about Abacus is that you can start with any amount, shares are purchased in 100 blocks, meaning if the share price is sh5 all you you need is sh500.
You'll need to decide what sort of investor you are, short, medium or long term. Short term is a little difficult in Kenya because order typically take 24 hours to fill. I'm personally a long term investor, I'm planning to hold the shares I have for the next 10 years at least. I look at the fundamentals of the company, revenue, profit and losses, dividends paid, the P/E ratio, who are in management, what are the future plans of the company according to them, how the overall industry is doing and finally what the future for the industry looks like.
Finally I should say like all investments there's a potential to lose your money, and share are more risky than most, as you start out only put in money that you can afford to lose and as you get more comfortable and familiar with stocks add to it. Remember to have a diverse portfolio, no more than 30%(my own number) of the money you save should be in one particular investment.
Good luck
