they're regulated and fairly well regulated; if you don't know someone who already uses one they'd recommend, in the UK you can go to Unbiased and get a list of local financial advisors and get a free session with them to get a feel for whether you feel comfortable with them as well as what they do

if you don't know enough about investing to feel comfortable having that conversation, you can start at the FCA site to get the basics. is the feeling ridiculous thing imposter syndrome? because *everyone* deserves to get professional advice to make more of their pennies, not just the rich!