I think you are just starting out and dont have the budget or experience yet to print your own it is always best to outsource first. This saves you from having to invest in equipment and you can use that money in other areas to market your company and build a bigger customer base.
It is always good to have the customer base to support the cost of business. Also I would check with the printer down the street and see what type of minumums you are looking at for getting orders printed. If it is a screen printer chances are they will not print one shirt at a time for you. If this is what you are looking to do maybe your best best would be to find a
dtg printer that will work with small orders with you
Then while you are doing your business this way you can take the time and see what printing method would be best for your budget later and learn everything you can about it.
another way to be able to do the garments yourself for a fairly low price would be plasitol transfers as the only equipment purchase you would need to make is a heat press. You can then order plasitol transfers from a company such as F & M or one of the many other companies out there, and apply them as you get orders. That way you get a screen print quality but dont have to have a ton of garments printed at once that may not sell.
Well hope this helps some and gives you some direction on what to research
