Something to consider... even slight upgrades early on often improve your game enough that you get promoted sooner, and then as you move back, you start feeling the need to upgrade again...even using a "free rental" like a driver or irons can be enough to get you promoted and then you are back to your starter clubs on tees that are further away.
You still want to test them, but just don't do it in a ranked round unless you plan to buy.
delaying upgrades as long as possible can help. I waited until the L59 irons, which many recommended.
but, I started out on mobile, so to help me get there, I used the "coin rental clubs" sets and while they are not a huge change, they do start to offer high trajectory which makes them play better than the starter clubs. If you don't have the coins, use the time to learn course management.
Even with the best clubs on WGT and on the back tees, there will be times you can not reach the green in heavy winds on long par 4's... so... you need to think about where to lay up, and have a great short game... your wedges and pitches, flops, punch shot will bail you out of tough conditions.
You may want to consider upgrading a wedge first as your short game will help save you shots more than irons probably and there are some good wedges in the late 30's to early 40's I believe.