What BIZ can I start u with just 20k to 30k ? Pls I need decent advice

It's a tight one but I believe with determination you can do well even with as little as N20k

But you must b prepared to start small.

Now, given d capital limitation you may need to consider goods that are in high demands.

Such as computer & printer consumables, office stationeries that could b supplied to offices, u can also engage in sales of 1st grade but second-hand materials (clothes, shoes, kiddies wears etc)

You can also go into independent marketing of other companies' products for a commision till you can grow ur capital
Wish you all d best