Since you are a beginning AG brewer, my vote is a single infusion.
HOWEVER,
To me one of the joys of homebrewing, is that I can take an indentical set of simple ingredients and by using different processes I can get a variety of different results, and I'm not just talking using different yeast. If one mashes in at 145 for say 20 min, and then raises the temp to 160 for 20 min. you will get a different wort composition than if you just did a single infusion at 152 for 40 min. I'm not saying there will be a big difference in the final product, but it will be different. Some don't want to bother with the extra steps, others do. Strictly personal preference.
The maltsters have improved their product, but they don't have the perfect, say pale malt, for all English style beers. A little tweak here and there in the mash process can make the final product thinner, thicker, maltier, or drier - if that is what interests you.
Again, I'd advise a single infusion. Maybe after a few more, try a step mash, or if you are happy with your beers, don't bother. Some setups are easier for doing step mashes. If it would be a pain, don't bother