Switching from Sram to Shimano...how much of a transition?

I have had a hybrid for many years, and just purchased a Ruby Apex Compact. I thought learning to shift with SRAM vs. Shimano would be better due to my age (69), and hand size. Now I realize that bike tour companies use Shimano gearing. I have taken a European bike tour trip for many years, and wonder how difficult it will be for me to use Shimano on my next tour. As you can tell, I am completely new to a road bike! My thought is that it would be more difficult to switch from Shimano to SRAM, rather than the other way around. I did test ride a Shimano bike, but haven't ridden for any length of time.Now I'm feeling I made a wrong decision. The reason I bought a road bike was to improve my cycling skills in order to go on bike tours for as many years as possible.

Can you borrow someone's Shimano-equipped bike?

It really isn't a big deal, I promise. I have Shimano on my road bike and SRAM on my cross bike. You would have to get used to the two-lever system rather than the single lever, but it'll only let you push the smaller lever so far, and I think one or two missed shifts would get you used to it in a hurry. ;)

Thanks! I didn't think of that particular aspect when buying, and proceeded to worry too much! Yes, I could borrow/rent a Shimano. I will figure it out I'm sure. I always do a lot of research before purchasing anything, but once I buy, the anxiety sets in, LOL, and I start second guessing myself.