Well, if the US feels it necessary to send a carrier off somewhere detached from the Pacific Fleet, Wasp would be the most logical choice, since both she & Ranger are several knots slower than the other carriers, while Ranger's too lightly built to be exposed to sharp, pointy objects, & if somebody has to be sent to the Med, her airgroup, if composed similarly to OTL is about 3 dozen fighters & a similar number of dive bombers, would be more suited for conditions there, given the greater air threat & the Italian fleet no longer being a serious issue that'd require torpedo planes.
As for the escort situation, right now, as a crude guesstimate, the USN should have about about ~100 or so modern destroyers in service (59 of the assorted ~1500 ton types, 13 1850 ton 'leaders' which weren't fitted with DP guns to make treaty displacement limits & a couple dozen or so of the Benson/Livermore classes, though some are still working up, and few dozen more of those plus a handful of Fletchers will enter service later in 1942. There'll be over 100 more coming on line in 1943, but there's a lot that can happen before then.
On top of this, without the transfer of 50 WW1 flush-deck ships TTL, there's around 121 of those in service as destroyers (minus a few of the Asiatic Fleet units that have been lost & a couple others picked off by U-boats or wrecked in a storm if things in the Atlantic are going similar to OTL for the USN), plus the Allen (only survivor of the pre-flush deck, high-forecastle 1000 ton types) for second-line duty such as convoy escort, though many of those will need substantial overhaul work, and/or refitting before they can really be used, as well as 48 other flush-deck hulls in subsidary roles, 26 of which (the 18 fast minesweepers & 8 minelayers) retain all destroyer capabilities except torpedoes, & several more (the seaplane tender & APD conversions) that could be used to escort convoys if necessary.
Outside of destroyers, though I don't have precise numbers, there's several dozen other ships which have some use in coastal patrol, convoy escort, & other such work- the Coast Guard cutters, minesweepers, a few left-over "Eagle boats" from WW1, armed yachts & trawlers, etc.)
IOTL, the first DEs entered service in early 1943, though with that escort design that the RN ordered a few of from US yards, there should be something similar available somewhat faster TTL.
Still, with several carrier TFs, probably a surface action group or two, possibly needing to reinforce the contingent of the Asiatic Fleet still fighting in the DEI, & a bunch of convoys & ASW patrols, things are going to be awfully tight escort-wise until 1943, even if significant losses such as those of the OTL Guadalcanal campaign can be avoided.