Do you have other retirement investment vehicles (like a 401k) or is the Roth your only retirement account?
Generally, if you only have a Roth, and your total investment in the market is less than ~$250k, you're probably OK leaving it in a target date fund for now until it grows beyond 250k. You might now or eventually want to change the target-date fund to one 5 or 10 years past when you think you are going to retire, because these funds are super conservative on asset allocation and might be over-invested in safe bond-type funds on a faster path than you might want. But for now, 20 years out, it's probably only 95/5% stocks/bonds and doesn't make a difference.
If you have other retirement accounts available to you, like a 401k and a Roth, once you hit $250k total across all accounts, you might want to consider selling out of the target date funds completely and then re-allocating inside the different accounts based on tax advantages. Figure out your allocation for bonds and value- and blue-chip index funds and buy those in the 401k, then use your Roth to maximize the portion used for REITs, dividend stocks, long shots, and growth funds. That way you're getting the maximum tax-free growth in the most advantaged account. Save the bonds portion for the tax-deferred 401k.