Hey. Going to start with the TLDR: bite the bullet with a mindset of investing for 5 years minimum; join us over in the Freetrade forum, ask questions, watch the YouTube vids of Freetraders showing their investment strategies & read the official Freetrade blogs; don’t worry about an ISA for now (you can transition over to one when your Portfolio is bigger) but if you prefer one now there’s a fee-free period till end of June; the default basic Freetrade GIA is perfect for starters in my opinion so I’d say opt for this one as you dip your toe in the markets.
Anyway, the most helpful way I want to respond to this post is by showing you & other apprehensive account holders my Portfolio to date as a fellow newbie (onboarded autumn 2018):
I’ve loaded my account with £400 total to date to get the ball rolling while I’m still young & have incurred zero fees for doing so.
At first I was checking the app every day as investing is exciting (or ‘scary’ in the short-term) and you’ll find yourself wanting to tinker with your portfolio early on as you learn more & settle on which ETFs, brands and stocks you’re comfortable with.
Currently, I’m in the green! 
Over time, I check the app less often (once a month-ish now when the monthly statement comes through) as naturally you become accustomed/desensitised to the short-term fluctuations and that initial excitement/fear wears off psychologically eventually. This is the sweet spot that Freetrade have imho: the mission is long term “investing for everyone” and don’t nudge you into trading frequently (portfolio churn) like other platforms may do. Whether you put a lump sum in or/and invest little & often (aka pound cost averaging), you can leave the app alone in between in the knowledge that you’re putting your money to work at amounts tolerable to you.
Every now and then you’ll get a nice dividend notification which happened to me today:
Overall, hopefully this little insight helps, DYOR and just go for it. The best time to invest was yesterday, the second best time is now.
P.S. Obligatory sign off: this isn’t investment advice, please do your own research.