Looks fairly chubby and a good size I definitely say he's at least a yr or more, probably more. If he's recently been wc (wild caught) he'll be stressed for a while and will rarely take hand held food unless really hungry. I usually dump in 3-4 3/4"-<1" crickets every few days during the warmer months and 1-3 1-2x's/wk in colder. They poop GIANT poops about once a week or more so that's a good sign hes eating and not constipated. Start handling him after about a wk or so just to acclimate him and reduce initial stress, then hold him a lil each day to get him used to it if your planning on keeping him, if not try to keep contact to a minimum.
If he chuckles when you hold him it's a male and males usually have dark spots and patches under his chin. It he does his trill call again its a male for sure, females are silent.
I have 4 males( just brought one in cause he got stepped on) and 2 females and a few dozen toads in my yard plus a few thousand toad tadpoles in my pool!
Don't worry about any questions we all have to learn somehow and better to ask than not