Going to Disney 5/2017. First time visit with just my family so doing all the planning on my own. How do we get to Universal? it will be myself my husband and 2 children (age24&21) Don’t want to spend a lot in travel money, and we will not be renting a car. Thanks for any suggestions Im sure this question was asking a million of times 
Will you be going to Disney first?
Are you just going over to Universal for the day, or are you going to be staying at a UOR resort? Also, don’t rule out renting a car for your whole trip - with careful shopping, you can often get a deal that will save you money overall, especially if you stop off on the way to WDW to pick up some food and drinks so you aren’t paying top dollar for everything in the parks/resort.
I will be arriving on Sunday and staying POFC. I was planning on doing a one day universal trip park to park ticket. Maybe midweek. HUGE HUGE HP fans so will be spending most of the day there.
I think a one day car rental may be cheaper than Uber but I would price it out.
Remember to allow for parking charges at uni.(22) Plus the 1 day rental return times are quite early and you might need to keep it overnight if you are planning to stay until close.
HIGHLY HIGHLY suggest staying on site - you get in an hour early. We used a car service - Destination MCO - they were awesome
Pay for the convenience of a car service. Time is money when you are on vacation. I spent 2 hours one time returning a car - and it just burned me up
I’m with you on this one, @davidtyost! We used a car service from MCO to UOR and were onsite 30 minutes after we set foot off the plane. Well worth it!