Ok so lets imagine i am stepping into the dragons dens, and you guys are the dragons (though im not looking for money or investment...just advice for now)

I am a 29yr old male living in cape town and working as a GM at an engineering manufacturing company. I enjoy my work but every single day I dream about having my own business, and each day I dream, I lose a day I could have been running my very own business, as small as my ideas may be.

I would love to start a business in line with something I love, I love animals and I love food.

IDEA 1 - PET/AQUARIUM STORE: initially suppose to be an 'aquarium' store only but in the area I am eyeing, an aquarium store would not be enough as a large chunk of the community have dogs and Birds, the idea is now then an aquarium store which stock also small animals (cats/hamsters/rabbit) and a range of birds, and accessories, food and toys for all pets. The only issue with this one is start-up capital, it would require a large sum, while I have saved a sum, and intend to sell one of my cars as well, this will still not be enough, so would have to maybe look at investor or loan or or...

IDEA 2 - TAKE AWAY/FOOD: the idea is solid, the menu solid, the concept is there, but location is difficult one for me here, i have looked and looked and considered again and again but cannot decide on a suitable location for this type of business.

IDEA 3 - CONVENIENCE STORE(MINI SUPERMARKET): I have identified an area which requires this kind of business, the issue with this one is finding premises in this area, i am still looking however.

please bear in mind, these are ideas, who knows, i may end up opening a barber shop, the ultimate plan is to own my own business. i hope to start something up without leaving my current job just yet. i have a wife who is very much capable of managing a business for me,i will be available for the business after working hours and on weekends.
i would like some advice from the people here who have successfully started small businesses. what to look out for, what to avoid, i am very afraid, but i promised myself i need to start something before i am 30yrs old, infact i should have started long ago but every idea just does not seem right.

thank you all