First, work your way up. If you don't even have an enlarger, you have a long way to go. Making a print that doesn't totaly suck isn't that hard, but making a print that you'ed be willing to hang is. It's a lot cheaper to improve your skills on sheets of 8x10. You might even look for a club in your area where you can speed up the learning process.
Second, find an Omega 4x5 enlarger with an XL designation. Easy to find, relatively cheap. Plenty of head height.
Finally, use the single tray method for sheets over 11x14. I use 5 quart plastic pails from the home center to hold the various chemicals (easy to pour back and forth from the tray) and an old Kodak tray siphon so I never have to remove the print until the wash is finished (I have two trays so I can get at least a small start on the next iteration).
Enjoy the ride,