We had 3 months between ordering our first RV and taking delivery last March. We are not full timers, but "a lot of time on the roaders", last year 135 nights and 8,000 miles, including 3 one month trips, and we'll do about the same this year but will have one trip of almost 3 months.
My wife took full advantage of the opportunity to have a couple of shoping sprees at Crate and Barrel to outfit the kitchen (we eat in almost all the time, and she is an incredible chef, so it is all to my benefit
)...... She also got a Mini Max Big Green Egg which we use all the time, and was a great investment.
She did show some restraint, and I can say we use everything she purchased, although she decided to get a crock pot for some reason (she never had one) and I am not a fan of crock pot type cooking, other than chili which of course can just be cooked in a pot on the stove.......
We did use linens, towels, etc. that we had in the house. We also had some folding chairs for outside we moved from the house to the coach.
For tools, I got a soft sided tool bag, and transfereed what I thought I would need to have for travel into it, and move it between coach and home. I don't try to carry every conceivable tool with me, as you are seldom more than 30 minutes from a Home Depot etc. if by chance you need something special.
Other things we added as we determined we needed them, awning screen, TPMS, Safety Steer, etc., but I would not buy any of these types of things until you have used the coach for a while (TPMS maybe sooner than later though, I really like knowing what is going on, as much on the toad as the coach).
We still struggle with packing too many clothes, and over provisioning food to start out a trip.
And a couple of newbie tips; while we learned so much from iRV2 and a Tiffin forum, 2 things I learned the hard way. The corners / edges of slides are hard, and can be sharp, think about putting some kind of padding on them (something like pipe insulation, others use swim noodles; and you have to put the padding on once you get it for it to do any good). Before you dump your black tank, dump a little gray water first to ensure your connections are tight, because it's a lot better to find out with gray water.....
Don't sweat the small stuff, and I hope your enjoy your travels as much as we have!