wiring a detached garage
Then I would do the rest myself.
As an overview, though, if you do not have a breaker at your meter, you will need to arrange to have the power turned off by the electric company. You should also install a main breaker as a part of this project so you don't need to do so again.
You should run the circuit out of your main breaker box, not from your meter, even if that means using more wire. The splice should happen in an approved breaker box, not an ordinary junction box and DEFINITELY NOT just inside the conduit or on the meter conntection, itself (two wires coming from each connection is a HUGE hazard). Taking it from the main breaker box also makes it a more routine electrical project. You would use one of the slots in the main box to create a sub-panel circuit with a new feeder breaker that feeds out of the breaker box.
From there, you will need exterior grade cable (UF cable; NOT ordinary sheathed electrical cable/BX cable) at a gauge that will carry the amps you will need to service the new box. Bury the cable according to code from the meter to the entry point for the new box. You should also use metal conduit to bring the cable at either end of the underground run from the underground to an exterior-grade junction box, along with a special water-resistent rubber nipple for the underground cable to slide through into the metal conduit. You also should run metal conduit underneath any sidewalk or high-traffic area.
You should attach the metal conduit on the garage end to an outdoor, aluminum electrical box, and then tap into the garage through that box.
The ampacity (size) of the UF cable will depend upon what else you plan to put in the garage: how much electrical service you will need in the garage. Check out a chart at your local home center or, again, consult an electrician.
Also, make sure that you do not overpower your electrical service at your meter. Some homes are wired for 30, 60, or 100 or less amps. (Another judgement an electrician would better make.)
This is just an overview; there are other pitfalls. Again, I would hire it out.
my question is what would be a large enough wire size to run from my breaker box on the house, to the box i will be putting on the garage. i plan on putting another breaker box on the garage itself. i already have a 60amp breaker that is not being used on the house panel box so i will be coming out of that breaker and going to the one on the garage.
an electrician told me that a 6/3 wire should be enough but i just want to make sure that i dont under-rate anything. my house breaker panel is about 75 feet from the new garage and it has a 150amp main service breaker.
And that is based on nameplate ratings and not the size of of the circuit.
Both AC and welders can vary drastically in their loads.
Here is a lot of inforamtion about wiring detached garages.